Ch.8 SystemsofEquationsandInequalities
8.1 SystemsofLinearEquationsinTwoVariables
1 DecideWhetheranOrderedPairisaSolutionofaLinearSystem
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Determinewhetherthegivenorderedpairisasolutionofthesystem.
1) (1
,
–1)
x+y=0
x–y=2
A) solution B) notasolution
2) (–6
,
–3)
x+y=3
x–y=9
A) notasolution B) solution
3) (2
,
3)
2x+y=7
3x+2y=12
A) solution B) notasolution
4) (6
,
–6)
4x–y=18
2x+4y=–12
A) notasolution B) solution
5) (2
,
3)
2x–y=7
3x–2y=12
A) notasolution B) solution
6) (–4
,
3)
4x+y=–19
2x+4y=–20
A) notasolution B) solution
7) (–3
,
5)
2x=–1–y
3x=1–2y
A) solution B) notasolution
8) (–5
,
1)
3x=16–y
2x=13–3y
A) notasolution B) solution
Page1
2 SolveLinearSystemsbySubstitution
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Solvethesystemofequationsbythesubstitutionmethod.
1)
x+y=-
3
y=-
2x
A) {(3
,
–6)} B) {(3
,
6)} C) {(–3
,
–6)} D) {(–3
,
6)}
2)
–5x–3y =-
168
x=5y
A) {(30
,
6)} B) {(6
,
30)} C) {(30
,
–6)} D) {(31
,
6)}
3)
y=4x–3
2y+8x =26
A) {(2
,
5)} B) {(5
,
2)} C) {(–2
,
5)} D) ∅
4)
2y =x+4
3x+6y =0
A) {(–2
,
1)} B) {(1
,
–2)} C) {(–2
,
–1)} D) {(2
,
0)}
5)
y=4x+7
y=9x+6
A) 1
5,39
5B) 39
5,1
5C) {(1,11)} D) ∅
6)
4x+2y =162
x–4y =0
A) {(36
,
9)} B) {(9
,
36)} C) {(36
,
–9)} D) {(37
,
9)}
7) x–7y=40
–2x–8y=30
A) {(5
,
–5)} B) {(4
,
–4)} C) {(–5
,
–4)} D) ∅
8) 9x–6y=–12
4x–2y=–2
A) {(2
,
5)} B) {(1
,
6)} C) {(2
,
6)} D) ∅
9) 4x+y=11
–4x+5y=–5
A) 5
2,1 B) {(1,–9)} C) 5
,
–1 D) 7
2,–3
10) 3x–2y=2–3x
3x+7y=x+6y+4
A) {(1
,
2)} B) {(1
,
–2)} C) {(0,2)} D) 1
3,0
Page2
11) y=1
5x–5
y=1
3x–7
A) {(15
,
–2)} B) {(15
,
2)} C) {(25
,
0)} D) 16
5,–13
2
3 SolveLinearSystemsbyAddition
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Solvethesystembytheadditionmethod.
1) x+y=–9
x–y=16
A) {(3.5
,
–12.5)} B) {(3.5
,
12.5)} C) {(9
,
–12.5)} D) {(9
,
3.5)}
2) 4x +3y =-
2
–4x –9y =14
A) {(1,–2)} B) {(–1,2)} C) {(–1,–2)} D) ∅
3) 2x+7y=–10
2x+2y=20
A) {(16
,
–6)} B) {(–16
,
2)} C) {(–16
,
7)} D) {(–6
,
16)}
4) x+4y=–24
5x+3y=–35
A) {(–4
,
–5)} B) {(–5
,
–4)} C) {(4
,
–4)} D) ∅
5) 9x+y=–15
–3x–2y=10
A) –4
3,–3 B) {(1,9)} C) –2
,
–2 D) –1
3,–12
6) 8x+16y=16
3x–8y=–8
A) {(0,1)} B) {(1,0)} C) {(1,1)} D) {(0,0)}
7) 2x+20y=–162
8x+5y=27
A) {(9
,
–9)} B) {(–9
,
9)} C) {(8
,
–8)} D) {(–5
,
9)}
8) 7x+8y=–19
4x–3y=–26
A) {(–5
,
2)} B) {(–6
,
3)} C) {(–5
,
3)} D) ∅
9) 3x+7y=8
–7x+4y=–39
A) {(5
,
–1)} B) {(–5
,
1)} C) {(5
,
1)} D) {(–5
,
–1)}
10) 3y=24–6x
2x=40–3y
A) {(–4
,
16)} B) {(3
,
–16)} C) {(6
,
–16)} D) ∅
Page3
4 IdentifySystemsThatDoNotHaveExactlyOneOrdered –PairSolution
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Solvethesystembythemethodofyourchoice.Identifysystemswithnosolutionandsystemswithinfinitelymany
solutions,usingsetnotationtoexpresstheirsolutionsets.
1) x+y=6
x+y=–8
A) {(0,–2)} B) {(6
,
–8)} C) {(x,y) x+y=6} D) ∅
2) y=18–6x
6x+y=54
A) {(10
,
12)} B) {(12
,
6)}
C) {(x,y)6x+y=18}D)
∅
3) y=10–3x
9x+3y=30
A) {(0,10)} B) {(5,–5)}
C) {(x,y)3x+y=10}D)
∅
4) 3x +y=9
12x +4y =36
A) {(0,9)} B) {(5,–6)} C) {(x,y)3x+y=9}D)
∅
5) x+y=–5
x–y=11
A) {(3
,
–8)} B) {(3
,
8)} C) {(x,y)|x+y= –5} D) ∅
6) 4x–8y=8
–12x+24y=–32
A) {(3
,
4)} B) 1
3,–2
3
C) {(x,y) 4x–8y=8}D)
∅
7) x+5y=–21
7x+4y=–54
A) {(–6
,
–3)} B) {(–7
,
–2)}
C) {(x,y) x+5y=–21} D) ∅
8) 4y=43–5x
2x=58–4y
A) {(–5
,
17)} B) {(4
,
–17)}
C) {(x,y) 5x+4y=43}D)
∅
9) x–7y=8
2x–14y=16
A) {(8
,
0)} B) {(0,0)} C) {(x,y)|x–7y=8} D) ∅
10) y=–6x–5
18x+3y=–15
A) {(0,–5)} B) {(0,0)}
C) {(x,y)|6x+y=–5} D) ∅
Page4
11) 4x+y=7
2y=14–8x
A) 7
4,0 B) {(0,7)} C) {(x,y)|4x+y=7} D) ∅
12) y=1
3x+2
x–3y=–6
A) {(–6
,
0)} B) {(0,2)} C) {(x,y)|x–3y= –6} D) ∅
13) 9x–8y=4
–18x+16y=–16
A) 3
4,–2
3B) {(2
,
4)}
C) {(x,y)|9x–8y=4} D) ∅
14) x
2+y
2=–2
x–y=8
A) {(2
,
–6)} B) {(1
,
–5)} C) {(x,y) x–y=8}D)
∅
15) x
5+y
15 =1
x
4–y
12 =0
A) 5
2,15
2B) 15
2,5
2
C) (x,y) x
5+y
15 =1 D) ∅
5 SolveProblemsUsingSystemsofLinearEquations
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Solvetheproblem.
1) Thesumoftwonumbersis–9.Ifonenumberissubtractedfromtheother,theirdifferenceis5.Findthe
numbers.
A) –2
,
–7B)
–2
,
7C)2
,
–7D)
–10
,
1
2) Onenumberis1lessthanasecondnumber.Twicethesecondnumberis12 lessthan3timesthefirst.Findthe
twonumbers.
A) 14and15 B) 13and14 C) 15 and16 D) –15 and–14
3) Onenumberis2lessthanasecondnumber.Twicethesecondnumberis22 morethan5timesthefirst.Find
thetwonumbers.
A) –6and–4B)
–7and–5C)
–5 and–3D)4and6
4) Twocarsleaveacityandheadinthesamedirection.After3 hours,thefastercaris24milesaheadofthe
slowercar.Theslowercarhastraveled159miles.Findthespeedsofthetwocars.
A) 53mphand61mph B) 55 mphand63 mph
C) 80mphand88mph D) 45 mphand53 mph
Page5
Thefigureshowsthegraphsofthecostandrevenuefunctionsforacompanythatmanufacturesandsellsbinoculars.
Usetheinformationinthefiguretoanswerthequestion.
5) Howmanybinocularsmustbeproducedandsoldforthecompanytobreakeven?
A) 750binoculars B) 2250binoculars C) 1500binoculars D) 2700binoculars
6) Atthebreak–evenpointbothcostandrevenuearewhat?
A) $2250 B) $750 C) $1500 D) $2700
7) Morethanhowmanybinocularsmustbeproducedandsoldforthecompanytohaveaprofitgain?
A) 750binoculars B) 2250binoculars C) 1500binoculars D) 2700binoculars
8) Fewerthanhowmanybinocularsmustbeproducedandsoldforthecompanytohaveaprofitloss?
A) 750binoculars B) 2250binoculars C) 1500binoculars D) 2700binoculars
9) Usetherevenueandcostfunctionstowritetheprofitfunctionfromproducingandsellingxbinoculars.
A) P(x)=2x–1500 B) P(x)=2x+1500 C) P(x)=4x+1500 D) P(x)=4x–1500
10) Isthereaprofitwhen518binocularsareproduced?
A) No B) Yes
11) Isthereaprofitwhen889binocularsareproduced?
A) Yes B) No
12) Whatistheprofitwhen980binocularsareproduced?
A) $460 B) $3460 C) $2420 D) $5420
Solvetheproblem.
13) Steveinvestsinacircusproduction.Thecostincludesanoverheadof$24,000
,
plusproductioncostsof$5000
perperformance.Asold–outperformancebringsin$7000.Letxrepresentthenumberofsold–out
performancesandwritethecostfunction,Candrevenuefunction,R.
A) C(x)=24,000+5000x
R(x)=7000x
B) C(x)=24,000 +7000x
R(x)=5000x
C) C(x)=5000x
R(x)=24,000+7000x
D) C(x)=24,000x+5000
R(x)=7000x
14) Steveinvestsinacircusproduction.Thecostincludesanoverheadof$20,000
,
plusproductioncostsof$2000
perperformance.Asold–outperformancebringsin$4000.Determinethenumberofsold–outperformances,x,
neededtobreakeven.
A) 10performances B) 11performances C) 12 performances D) 4performances
Page6
15) Steveinvestsinacircusproduction.Thecostincludesanoverheadof$36,000
,
plusproductioncostsof$4000
perperformance.Asold–outperformancebringsin$7000.Determinethedollaramountcominginandgoing
outatthebreak–evenpoint.
A) $84,000 B) $48,000 C) $12 D) $22,909
16) An–Meiownsabusinessmakingandsellingjackets.Shehasafixedcostof$1960.Itcosts$95toproduceeach
jacket.Thesellingpriceis$123perjacket.Letxrepresentthenumberofjacketsproducedandsoldandwrite
thecostfunction,C,andrevenuefunction,R.
A) C(x)=95x+1960
R(x)=123x
B) C(x)=95 +123x
R(x)=1960x
C) C(x)=95 +1960x
R(x)=123
D) C(x)=95x+1960x
R(x)=123x
17) An–Meiownsabusinessmakingandsellingjackets.Shehasafixedcostof$900.Itcosts$92toproduceeach
jacket.Thesellingpriceis$107perjacket.Determinethenumberofjacketsthatmustbemadeandsoldin
ordertobreakeven.
A) 60units B) 61units C) 62 units D) 8units
18) Youinvested$41,800andstartedabusinesssellingvases.Suppliescost$19 pervaseandyouaresellingeach
vasefor$38.Letxrepresentthenumberofvasesproducedandsoldandwritethecostfunction,C,and
revenuefunction,R.
A) C(x)=19x+41,800
R(x)=38x
B) C(x)=19x+38
R(x)=41,800x
C) C(x)=19x+41,800
R(x)=38
D) C(x)=19x+41,800x
R(x)=38x
19) Youinvested$17,000andstartedabusinesssellingvases.Suppliescost$16 pervaseandyouaresellingeach
vasefor$33.Determinethenumberofvases,x,thatmustbeproducedandsoldtobreakeven.
A) 1000units B) 1001 units C) 1002 units D) 341 units
20) Asthepriceofaproductincreases,thedemandforthatproductdecreases.However,athigherprices,
suppliersarewillingtoproducegreaterquantitiesoftheproduct.Theweeklysupplyanddemandmodelsfor
acertaintypeoftelevisionareasfollows:
Demand:N=–3p+650
Supply:N=2.5p
wherepisthepriceindollarspertelevision.
Howmanyofthesetelevisionscanbesoldandsuppliedat$120pertelevision?
A) sold:290;supplied:300 B) sold:1010;supplied:300
C) sold:290;supplied:950 D) sold:300;supplied:290
21) Asthepriceofaproductincreases,thedemandforthatproductdecreases.However,athigherprices,
suppliersarewillingtoproducegreaterquantitiesoftheproduct.Theweeklysupplyanddemandmodelsfor
acertaintypeoftelevisionareasfollows:
Demand: N=–6p+680
Supply: N=2.3p
wherepisthepriceindollarspertelevision.
Findthepriceatwhichsupplyanddemandareequal.Atthisprice,howmanytelevisionscanbesuppliedand
soldeachweek?
A) $81.93;188 B) $183.78;423 C) $293.04;674 D) $81.93;205
Page7
22) InMiguelʹshometown,thepercentageofwomenwhosmokeisincreasingwhilethepercentageofmenwho
smokeisdecreasing.Thefunctiony=0.26x+16.7modelsthepercentage,y,ofwomeninthiscitywhosmokex
yearsafter1990.Thefunction0.20x+y=27.1modelsthepercentage,y,ofmeninthiscitywhosmokexyears
after1990.Usethesemodelstodeterminewhenthepercentageofwomenwhosmokewillbethesameasthe
percentageofmenwhosmoke.Roundtothenearestyear.Whatpercentageofwomenandwhatpercentageof
men(tothenearestwholepercent)willsmokeatthattime?
A) 2013;23% B) 2014;22% C) 2012;23% D) 2015;22%
23) In1985,inthetownofAppleby,20.1%ofHispanicswereoverweight,increasingbyanaverageof0.48%per
year.In1985,inthetownofAppleby,0.17%ofwhiteswereoverweight,increasingbyanaverageof27.7%per
year.Writeafunctionthatmodelsthepercentage,y,ofHispanicswhoareoverweightxyearsafter1985.Write
afunctionthatmodelsthepercentage,y,ofwhiteswhoareoverweightxyearsafter1985.
A) Hispanics:y=0.48x+20.1
Whites:y=27.7x+0.17
B) Hispanics:y=20.1x+0.48
Whites:y=0.17x+27.7
C) Hispanics:y=20.58x
Whites:y=27.87x
D) Hispanics:y+0.48x=20.1
Whites:y+27.7x=0.17
24) In1985,inthetownofAppleby,22.0%ofHispanicswereoverweight,increasingbyanaverageof0.41%per
year.In1985,inthetownofAppleby,0.18%ofwhiteswereoverweight,increasingbyanaverageof32.8%per
year.Ifthesetrendscontinue,inwhichyearwillthepercentageofHispanicswhoareoverweightbethesame
asthepercentageofwhiteswhoareoverweight?Roundtothenearestyear.WhatpercentageofHispanics(to
thenearestwholepercent)willbeoverweightatthattime?
A) 1986;22% B) 1988;23% C) 1984;21% D) 1982;21%
25) InthetownofMiltonLake,thepercentageofwomenwhosmokeisincreasingwhilethepercentageofmen
whosmokeisdecreasing.
Letxrepresentthenumberofyearssince1990andyrepresentthepercentageofwomeninMiltonLakewho
smoke.Thegraphofyagainstxincludesthedatapoints(0,17.5)and(12,20.86).Letxrepresentthenumberof
yearssince1990andyrepresentthepercentageofmeninMiltonLakewhosmoke.Thegraphofyagainstx
includesthedatapoints(0,28.9)and(14,26.1).
Determinewhenthepercentageofwomenwhosmokewillbethesameasthepercentageofmenwhosmoke.
Roundtothenearestyear.Whatpercentageofwomenandwhatpercentageofmen(tothenearestwhole
percent)willsmokeatthattime?
[Hint:firstfindtheslope–interceptequationofthelinethatmodelsthepercentage,y,ofwomenwhosmokex
yearsafter1990andtheslope–interceptequationofthelinethatmodelsthepercentage,y,ofmenwhosmoke
xyearsafter1990]
A) 2014;24% B) 2018;23% C) 2012;25% D) 2016;24%
26)
ohnnyʹscafeservesdesserts.Oneservingoficecreamandtwoservingsofblueberrypieprovides790 calories.
Threeservingsoficecreamandtwoservingsofblueberrypieprovides1290calories.Findthecaloriccontentof
eachitem.
A) Servingoficecream:250calories
Servingofblueberrypie:270calories
B) Servingoficecream:270calories
Servingofblueberrypie:250calories
C) Servingoficecream:232calories
Servingofblueberrypie:279calories
D) Servingoficecream:270calories
Servingofblueberrypie:260calories
27) Avendorsellshotdogsandbagsofpotatochips.Acustomerbuys3 hotdogsand2bagsofpotatochipsfor
$9.00.Anothercustomerbuys5hotdogsand4bagsofpotatochipsfor$16.00.Findthecostofeachitem.
A) $2.00forahotdog;$1.50forabagofpotatochips
B) $1.50forahotdog;$2.00forabagofpotatochips
C) $2.25forahotdog;$1.75forabagofpotatochips
D) $2.00forahotdog;$1.75forabagofpotatochips
Page8
28) TheFamilyFineArtsCentercharges$21 peradultand$15 perseniorcitizenforitsperformances.Onarecent
weekendeveningwhen525peoplepaidadmission,thetotalreceiptswere$8973.Howmanywhopaidwere
seniorcitizens?
A) 342seniorcitizens B) 183seniorcitizens C) 252 seniorcitizens D) 273 seniorcitizens
29) Abanktellerhas43$10and$5billsinhercashdrawer.Thevalueofthebillsis$280.Howmany$10 billsare
there?
A) 13$10bills B) 30$10 bills C) 15 $10 bills D) 28$10 bills
30) Arectangularlotwhoseperimeteris460 feetisfencedalongthreesides.Anexpensivefencingalongthelotʹs
lengthcosts$19perfoot,andaninexpensivefencingalongthetwosidewidthscostsonly$8perfoot.Thetotal
costofthefencingalongthethreesidescomesto$4130.Whatarethelotʹsdimensions?
A) Length150ft;Width80ft B) Length152 ft;Width78ft
C) Length146ft;Width84ft D) Length300 ft;Width160ft
31) Atwin–enginedaircraftcanfly1024milesfromcityAtocityBin4 hourswiththewindandmakethereturn
tripin8hoursagainstthewind.Whatisthespeedofthewind?
A) 64mph B) 48mph C) 80 mph D) 96mph
32)
J
ulieandEricrowtheirboat(ataconstantspeed)27 milesdownstreamfor3 hours,helpedbythecurrent.
Rowingatthesamerate,thetripbackagainstthecurrenttakes9hours.Findtherateofthecurrent.
A) 3mph B) 6mph C) 4 mph D) 2.5 mph
33)
J
amilalwaysthrowsloosechangeintoapencilholderonhisdeskandtakesitouteverytwoweeks.Thistimeit
isallnickelsanddimes.Thereare2timesasmanydimesasnickels,andthevalueofthedimesis$0.90more
thanthevalueofthenickels.HowmanynickelsanddimesdoesJamilhave?
A) 6nickelsand12dimes B) 7 nickelsand14 dimes
C) 5nickelsand10dimes D) 12 nickelsand6 dimes
34) Aflatrectangularpieceofaluminumhasaperimeterof66 inches.Thelengthis9incheslongerthanthewidth.
Findthewidth.
A) 12inches B) 21inches C) 30 inches D) 33inches
35)
J
arodishavingaproblemwithrabbitsgettingintohisvegetablegarden,sohedecidestofenceitin.Thelength
ofthegardenis5feetmorethan3timesthewidth.Heneeds74feetoffencingtodothejob.Findthelength
andwidthofthegarden.
A) length:29feet;width:8feet B) length:56 3
4feet;width:17 1
4feet
C) length:32feet;width:9feet D) length:26 feet;width:7feet
8.2 SystemsofLinearEquationsinThreeVariables
1 VerifytheSolutionofaSystemofLinearEquationsinThreeVariables
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Determineifthegivenorderedtripleisasolutionofthesystem.
1) (4
,
–2
,
–3)
x+y+z=–1
x–y+5z=–9
5x+y+z=15
A) solution B) notasolution
Page9
2) (–3
,
–5
,
4)
x+y+z=–4
x–y+4z=–3
2x+y+z=0
A) notasolution B) solution
3) (0
,
5
,
–4)
x–y+5z=–25
5x+z=–4
x+4y+z=16
A) solution B) notasolution
4) (1
,
3
,
0)
x–y+5z=2
5x +z=1
x+3y+z=10
A) notasolution B) solution
5) (1
,
–3
,
–4)
x–y+z=0
x+y+z=–6
x+y–z=2
A) solution B) notasolution
6) (–2
,
1
,
–3)
x–y+z=2
x+y+z=–4
x+y–z=0
A) notasolution B) solution
7) (–2
,
–1
,
4)
x+3y+5z=15
2y+2z=6
z=4
A) solution B) notasolution
8) (5
,
1
,
3)
x+5y+3z=23
3y+5z=28
z=5
A) notasolution B) solution
9) (–5
,
–1
,
3)
5x+2y+z=–24
2x–2y–z=–11
2x+y+3z=–2
A) solution B) notasolution
10) (–2
,
4
,
–3)
2x+2y+z=0
4x–4y–z=–26
2x+y+4z=–10
A) notasolution B) solution
Page10
2 SolveSystemsofLinearEquationsinThreeVariables
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Solvethesystemofequations.
1) x+y+z=2
x–y+2z=–3
2x+y+z=0
A) {(–2
,
3
,
1)} B) {(3
,
–2
,
1)} C) {(1
,
3
,
–2)} D) {(1
,
–2
,
3)}
2) x–y+2z=4
3x +z=3
x+4y+z=11
A) {(0
,
2
,
3)} B) {(2
,
0
,
3)} C) {(3
,
2
,
0)} D) {(3
,
0
,
2)}
3) x–y+z=3
x+y+z=–5
x+y–z=–1
A) {(1
,
–4
,
–2)} B) {(1
,
–2
,
–4)} C) {(–4
,
–2
,
1)} D) {(–2
,
1
,
–4)}
4) x+2y+5z=–12
5y+5z=–30
z=–1
A) {(3
,
–5
,
–1)} B) {(3
,
–1
,
–5)} C) {(–1
,
–5
,
3)} D) {(–5
,
3
,
–1)}
5) 4x+5y+z=–7
4x–4y–z=19
3x+y+4z=22
A) {(2
,
–4
,
5)} B) {(2
,
5
,
–4)} C) {(5
,
–4
,
2)} D) {(–4
,
2
,
5)}
6) x–y+2z=4
5x +z=0
x+5y+z=–20
A) {(0
,
–4
,
0)} B) {(0
,
0
,
–4)} C) {(–4
,
0
,
0)} D) {(0
,
–4
,
4)}
7)
x+y=7
5x +2y +5z =51
x–z=-
1
A) {(4
,
3
,
5)} B) {(4
,
5
,
3)} C) {(5
,
3
,
4)} D) {(5
,
4
,
3)}
8)
y–5z =12
–2x +y–3z =0
–2x +3z =-
14
A) {(4
,
2
,
–2)} B) {(4
,
7
,
–1)} C) {(7
,
3
,
0)} D) {(7
,
14
,
0)}
9) x+y+z=9
x–y+2z=4
2x+2y+2z=11
A) {(2
,
4
,
3)} B) {(3
,
4
,
2)} C) {(3
,
2
,
4)} D) ∅
Page11
10) –32+4z=4(x–3y)
2(x–4y–z)=–18
–4(2x+y)+3z=16
A) {(–1
,
1
,
4)} B) {(–1
,
4
,
4)} C) {(–1
,
2
,
8)} D) {(–1
,
–4
,
4)}
3 SolveProblemsUsingSystemsinThreeVariables
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Solvetheproblem.
1) Thesumofthreenumbersis–6.Ifthesecondnumberissubtractedfromthesumofthefirstandthird
numbers,theresultis4.Ifthethirdnumberissubtractedfromthesumofthefirstandsecondnumbers,the
resultis–8.Findthethreenumbers.
[Hint:letxrepresentthefirstnumber,ythesecondnumber,andzthethirdnumber.Usethegivenconditions
towriteandsolveasystemofequations.]
A) x=–2
,
y=–5
,
z=1B)x= –1
,
y= –5
,
z=0
C) x=–1
,
y=–4
,
z=–1D)x= –4
,
y= –3
,
z=1
2) Thefollowingisknownaboutthreenumbers:Ifthesecondnumberissubtractedfromthesumofthefirst
numberand2timesthethirdnumber,theresultis2.Thethirdnumberplus2timesthefirstnumberis3.The
firstnumberplus4timesthesecondnumberplusthethirdnumberis19.Findthethreenumbers.
[Hint:letxrepresentthefirstnumber,ythesecondnumber,andzthethirdnumber.Usethegivenconditions
towriteandsolveasystemofequations.]
A) x=0
,
y=4
,
z=3B)x=1
,
y=5
,
z=3C)x= –1
,
y=4
,
z=5D)x=0
,
y=3
,
z=7
3) Findthevaluesofa,b,andcsuchthatthegraphofthequadraticequationy=ax2+bx+cpassesthroughthe
points(–1,2),(3,14),and(4,12).
A) a=–1;b=5;c=8B)a=–1;b=8;c=5C)a=1;b=5;c=8D)a=1;b=8;c=5
4) Youthrowaballstraightupfromarooftop.Theballmissestherooftoponitswaydownandeventuallystrikes
theground.Amathematicalmodelcanbeusedtodescribetherelationshipfortheballʹsheightabovethe
ground,y,afterxseconds.Considerthefollowingdata:

x,secondsafter
ballisthrown
y,ballʹsheight,infeet,
abovetheground
194
2 126
494
Findthequadraticfunctiony=ax2+bx+cwhosegraphpassesthroughthegivenpoints.
A) y=–16x2+80x+30 B) y=–12x2+80x+26
C) y=–16x2+60x+50 D) y=–10x2+100x+4
Page12
5) ThetableshowsthepercentageofpeoplelivingbelowthepovertylineinoneU.S.cityintheyears2000
through2003.

Year
Percentageofpeopleliving
belowpovertyline
2000 11.2
2001 12.6
2002 13.2
2003 13
Thedatainthetablecanbewrittenasorderedpairs(x,y)wherexisthenumberofyearsafter2000andyisthe
percentageofpeoplelivingbelowthepovertylineinthatyear.Usethedatafor2000,2002,and2003tofind
thequadraticfunctiony=ax2+bx+cthatmodelsthepercentage,y,ofpeopleinthiscitylivingbelowthe
povertylinexyearsafter2000.
[Hint:Finda,b,andcbysubstitutingeachofthreeorderedpairsintothefunctionandwritingandsolvinga
systemoflinearequationsinthreevariables.]
A) y=–0.4x2+1.8x+11.2 B) y=–0.2x2+1.4x+11.2
C) y=–0.6x2+2.2x+11.2 D) y=–0.2x2+1.2x+11.2
6) Abasketballplayerscored26pointsinagame.Thenumberofthree–pointfieldgoalstheplayermadewas2
lessthanthreetimesthenumberoffreethrows(eachworth1point).Twicethenumberoftwo–pointfieldgoals
theplayermadewas8morethanthenumberofthree–pointfieldgoalsmade.Findthenumberoffree–throws,
two–pointfieldgoals,andthree–pointfieldgoalsthattheplayermadeinthegame.
A) 2freethrows;6two–pointfieldgoals;4 three–pointfieldgoals
B) 3freethrows;6two–pointfieldgoals;7 three–pointfieldgoals
C) 2freethrows;7two–pointfieldgoals;6 three–pointfieldgoals
D) 2freethrows;4two–pointfieldgoals;6three–pointfieldgoals
7) Avendorsellshotdogs,bagsofpotatochips,andsoftdrinks.Acustomerbuys5hotdogs,4bagsofpotato
chips,and5softdrinksfor$17.00.Thepriceofahotdogis$1.25morethanthepriceofabagofpotatochips.
Thecostofasoftdrinkis$2.25lessthanthepriceoftwohotdogs.Findthecostofeachitem.
A) $1.75forahotdog;$0.50forabagofpotatochips;$1.25 forasoftdrink
B) $0.50forahotdog;$1.75forabagofpotatochips;$1.25 forasoftdrink
C) $1.75forahotdog;$1.25forabagofpotatochips;$0.50 forasoftdrink
D) $2.00forahotdog;$0.75forabagofpotatochips;$1.25 forasoftdrink
8) Astoresellstents,sleepingbags,andcampstools.Acustomerbuysatent,5 sleepingbags,and2 campstools
for$227.Thepriceofthetentis9timesthecostofacampstool.Thecostofasleepingbagis$23morethanthe
costofacampstool.Findthecostofeachitem.
A) $63foratent;$30forasleepingbag;$7 foracampstool
B) $63foratent;$30forasleepingbag;$8 foracampstool
C) $63foratent;$35forasleepingbag;$12 foracampstool
D) $72foratent;$30forasleepingbag;$8 foracampstool
9) Threetrainsoneeastbound,onewestbound,andonenorthboundleaveacityatthesametime.Thespeed
ofthenorthboundtrainis10milesperhourgreaterthanthespeedoftheeastboundtrain.After3hours,the
distancebetweenthewestboundtrainandtheeastboundtrainis240miles.Twicethespeedofthewestbound
trainis60milesperhourmorethanthespeedofthenorthboundtrain.Findthespeedsofthethreetrains.
A) eastbound,30mph;westbound,50 mph;northbound,40 mph
B) eastbound,40mph;westbound,50 mph;northbound,50 mph
C) eastbound,20mph;westbound,60 mph;northbound,40 mph
D) eastbound,40mph;westbound,50 mph;northbound,30 mph
Page13
10) Ronattendsacocktailparty(withhisgraphingcalculatorinhispocket).Hewantstolimithisfoodintaketo
120gprotein,105gfat,and159gcarbohydrate.Accordingtothehealthconscioushostess,themarinated
mushroomcapshave3gprotein,5gfat,and9gcarbohydrate;thespicymeatballshave14gprotein,7gfat,
and15gcarbohydrate;andthedeviledeggshave13gprotein,15gfat,and6gcarbohydrate.Howmanyof
eachsnackcanheeattoobtainhisgoal?
A) 8mushrooms;5meatballs;2eggs B) 5 mushrooms;2 meatballs;8eggs
C) 2mushrooms;8meatballs;5eggs D) 9 mushrooms;6 meatballs;3eggs
11) Ms.Adamsreceivedabonuscheckfor$12,000.Shedecidedtodividethemoneyamongthreedifferent
investments.Withsomeofthemoney,shepurchasedamunicipalbondpaying5.5%simpleinterest.She
investedtwicetheamountshepaidforthemunicipalbondinacertificateofdepositpaying4.1%simple
interest.Ms.Adamsplacedthebalanceofthemoneyinamoneymarketaccountpaying3.1%simpleinterest.If
Ms.Adamsʹtotalinterestforoneyearwas$460,howmuchwasplacedineachaccount?
A) municipalbond:$2000
certificateofdeposit:$4000
moneymarket:$6000
B) municipalbond:$1500
certificateofdeposit:$3000
moneymarket:$7500
C) municipalbond:$2500
certificateofdeposit:$5000
moneymarket:$4500
D) municipalbond:$1750
certificateofdeposit:$3500
moneymarket:$6750
12) TheLittleTownArtsCentercharges$22 foradults,$18 forseniorcitizens,and$7forchildrenunder12for
theirliveperformancesonSundayafternoon.ThispastSunday,thepaidrevenuewas$10,932for716tickets
sold.Therewere41morechildrenthanadults.Howmanychildrenattended?
A) 256children B) 215children C) 245 children D) 246 children
13) Aceramicsworkshopmakesservingbowls,platters,andbreadbasketstosellatitsWinterFestival.Aserving
bowltakes3hourstoprepare,2hourstopaint,and8hourstofire.Aplattertakes16hourstoprepare,3hours
topaint,and4hourstofire.Abreadbaskettakes4hourstoprepare,16hourstopaint,and7hourstofire.If
theworkshophas123hoursforpreptime,97hoursforpainting,and120hoursforfiring,howmanyofeach
canbemade?
A) 9servingbowls,5platters,4breadbaskets B) 5 servingbowls,4platters,9breadbaskets
C) 4servingbowls,9platters,5breadbaskets D) 10 servingbowls,6platters,5breadbaskets
14) Aceramicsworkshopmakeswreaths,trees,andsleighsforsaleatChristmas.Awreathtakes3hoursto
prepare,2hourstopaint,and8hourstofire.Atreetakes14hourstoprepare,3hourstopaint,and4hoursto
fire.Asleightakes4hourstoprepare,15hourstopaint,and7hourstofire.Iftheworkshophas85hoursfor
preptime,56hoursforpainting,and86hoursforfiring,Howmanyofeachcanbemade?
A) 7wreaths,4trees,2sleighs B) 4 wreaths,2 trees,7sleighs
C) 2wreaths,7trees,4sleighs D) 8 wreaths,5 trees,3sleighs
15) ThreeshrimpboatssupplytheshrimpwholesalersonHiltonHeadwithfreshcatch.TheAnnabelletakes50%
ofitscatchtoHudsonʹs,20%toCaptainJʹs,and30%toMainstreet.TheCurlyQtakes40%ofitscatchto
Hudsonʹs,40%toCaptainJʹs,and20%toMainstreet.TheSloJoetakes30%ofitscatchtoHudsonʹs,40%to
CaptainJʹs,and30%toMainstreet.OneweekHudsonʹsreceived248.8poundsofshrimp,CaptainJʹsreceived
216.8pounds,andMainstreetreceived163.4pounds.Howmanypoundsofshrimpdideachboatcatch?
A) Annabelle174lbs,CurlyQ253lbs,SloJoe202 lbs
B) Annabelle253lbs,CurlyQ202lbs,SloJoe174 lbs
C) Annabelle202lbs,CurlyQ253lbs,SloJoe174 lbs
D) Annabelle202lbs,CurlyQ174lbs,SloJoe253 lbs
Page14
16) Adelisellsthreesizesofturkeysandwiches:thesmallturkey sandwichcontains4ouncesofmeatandsellsfor
$3.50;theregularturkeysandwichcontains7ouncesofmeatandsellsfor$4.00;andthelargeturkeysandwich
contains11ouncesofmeatandsellsfor$4.50.Acustomerrequestsaselectionofeachsizeforareception.She
andthemanageragreeonacombinationof42sandwichesmadefrom18pounds6ouncesofturkeyforatotal
costof$166.Howmanyofeachsizesandwichwillbeinthiscombination?(Note:1pound=16ounces)
A) 16smallsandwiches,14mediumsandwiches,12 largesandwiches.
B) 18smallsandwiches,8mediumsandwiches,16 largesandwiches.
C) 12smallsandwiches,10mediumsandwiches,20 largesandwiches.
D) 14smallsandwiches,20mediumsandwiches,8 largesandwiches.
17) Arealestateinvestorisexaminingatriangularplotofland.Shemeasureseachangleofthefield.Thesumof
thefirstandsecondanglesis160°morethanthemeasureofthethirdangle.Ifthemeasureofthethirdangleis
subtractedfromthemeasureofthesecondangle,theresultisthricethemeasureofthefirstangle.Findthe
measureofeachangle.(Note:Thesumoftheanglesofatriangleis180°.)
A) Firstangleis40°
,
secondangleis130°
,
thirdangleis10°
B) Firstangleis46°
,
secondangleis126°
,
thirdangleis8°
C) Firstangleis38°
,
secondangleis130°
,
thirdangleis8°
D) Firstangleis44°
,
secondangleis132°
,
thirdangleis4°
8.3 PartialFractions
1 DecomposeP/Q,WhereQHasOnlyDistinctLinearFactors
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Writetheformofthepartialfractiondecompositionoftherationalexpression.Itisnotnecessarytosolveforthe
constants.
1) 2x–1
(x+6)(x+2)
A) A
x+6+B
x+2B) A
x+6+B
x+2+C
(x+6)(x+2)
C) A
x+6+B
x+2+Cx+D
(x+6)(x+2) D) A
x+6+B
x+2+C
(x+6)2(x+2)2
2) 6x–3
x2–13x+42
A) A
x–6+B
x–7B) A
x–6+B
x–7+C
x2–13x+42
C) A
x–6+B
x–7+Cx+D
x2–13x+42 D) A
x–6+B
x–7+C
(x–6)2(x–7)2
Writethepartialfractiondecompositionoftherationalexpression.
3) x–7
(x–2)(x–3)
A) 5
x–2+–4
x–3B) –4
x–2+5
x–3C) 5
x–2+4
x–3D) 4
x–2+–5
x–3
4) x
(x–2)(x–3)
A) –2
x–2+3
x–3B) 2
x–2+–3
x–3C) –3
x–2+2
x–3D) –2
x–2+–3
x–3
Page15
5) x
x2+3x+2
A) 2
x+2+–1
x+1B) –2
x+2+1
x+1C) 1
x+2+–2
x+1D) 2
x+2+1
x+1
6) 2x2–x–15
x(x+1)(x–1)
A) 15
x+–6
x+1+–7
x–1B) 15
x+6
x+1+–7
x–1C) 15
x+–6
x+1+7
x–1D) 15
x+–7
x+1+6
x–1
7) 4x2–x–17
x3–x
A) 17
x+–6
x+1+–7
x–1B) 17
x+6
x+1+–7
x–1C) 17
x+–6
x+1+7
x–1D) 17
x+–7
x+1+6
x–1
8) 13x–18
(x–1)(x–2)
A) 5
x–1+8
x–2B) 12
x–1+1
x–2C) 4
x–1+9
x–2D) 5
x–1+–8
x–2
9) 8x–12
x2+2x–24
A) 6
x+6+2
x–4B) 6
x+6+–2
x–4C) 7
x+6+1
x–4D) 6
x–6+2
x+4
10) 14x2–61x–90
x(x–6)(x–5)
A) –3
x+8
x–6+9
x–5B) –3
x+9
x–6+8
x–5C) –3
x+7
x–6+10
x–5D) x+8
x2–6
+9
x–5
2 DecomposeP/Q,WhereQHasRepeatedLinearFactors
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Writetheformofthepartialfractiondecompositionoftherationalexpression.Itisnotnecessarytosolveforthe
constants.
1) 4x–1
(x–2)2
A) A
x–2+B
(x–2)2B) A
x–2+Bx+C
(x–2)2
C) A
x–2+B
x–2+Cx+D
(x–2)2D) A
x–2+B
x–2+C
(x–2)2
Page16
2) 5x+2
(x+7)(x+1)2
A) A
x+7+B
x+1+C
(x+1)2B) A
x+7+B
x+1+C
x+1+Dx+E
(x+1)2
C) A
x+7+B
x+1+Cx+D
(x+1)2D) A
x+7+B
x+1+C
x+1+D
(x+1)2
Writethepartialfractiondecompositionoftherationalexpression.
3) 8x+6
(x–3)2
A) 8
x–3+30
(x–3)2B) 8
x–3+48
(x–3)2C) 8
x–3+x+30
(x–3)2D) 1
x–3+x+30
(x–3)2
4) 2x2–2x+4
(x–1)3
A) 2
x–1+2
(x–1)2+4
(x–1)3B) 2
x–1+2
(x–1)2
C) 2
x–1+x+2
(x–1)2+x2+4
(x–1)3D) 2
x–1–2
(x–1)2+4
(x–1)3
5) x+2
x3–2x2+x
A) 2
x+–2
x–1+3
(x–1)2B) 2
x+3
x–1+–2
(x–1)2
C) 2
x+–2
x–1+5
(x–1)2D) –2
x+2
x–1+3
(x–1)2
6) 36–7x
x3–6x2+9x
A) 4
x+–4
x–3+5
(x–3)2B) 4
x+5
x–3+–4
(x–3)2
C) 4
x+–4
x–3+10
(x–3)2D) –4
x+4
x–3+5
(x–3)2
7) 10x2+24x+13
(x+2)(x+1)2
A) 5
x+2+5
x+1+–1
(x+1)2B) –5
x+2+5
x+1+1
(x+1)2
C) 5
x+2+–5
x+1+–1
(x+1)2D) –1
x+2+5
x+1+–5
(x+1)2
Page17
8) 64–11x
x(x–4)2
A) 4
x+–4
x–4+5
(x–4)2B) 4
x+5
x–4+–4
(x–4)2
C) 4
x+–4
x–4+10
(x–4)2D) –4
x+4
x–4+5
(x–4)2
3 DecomposeP/Q,WhereQHasaNonrepeatedPrimeQuadraticFactor
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Writetheformofthepartialfractiondecompositionoftherationalexpression.Itisnotnecessarytosolveforthe
constants.
1) 3x+4
(x+7)(x2+x+5)
A) A
x+7+Bx+C
x2+x+5B) A
x+7+B
x2+x+5
C) A
x+7+B
x2+x+5
+C
(x+7)(x2+x+5) D) A
x+7+Bx+C
x2+x+5
+D
(x+7)(x2+x+5)
Writethepartialfractiondecompositionoftherationalexpression.
2) 8x+1
x3–1
A) 3
x–1+–3x+2
x2+x+1B) 3
x–1+–3
x+1+2
x–1
C) –3
x–1+3x+2
x2+x+1D) 3
x–1+2x–3
x2+x+1
3) 8x2+10x+28
(x+2)(x2+6)
A) 4
x+2+4x+2
x2+6B) 4
x+2+4
x2+6
C) 4
x+2+4x–2
x2+6D) 4
x+2+4
x+6+2
(x+6)2
4) 7x2+21x+10
x3+4x2+3x+12
A) 2
x+4+5x+1
x2+3B) 2
x+4+5
x2+3
C) 2
x+3+5x+1
x2+4D) 2
x+4+5
x+3+1
(x+3)2
Page18
5) –13x+84
(x+4)2(x2+1)
A) 3
x+4+8
(x+4)2+–3x+4
x2+1B) 3
x+4+8
(x+4)2+–3
x2+1
C) 3
x+4+12
(x+4)2+–3x–4
x2+1D) 12x–4
(x+4)2+–3x+4
x2+1
6) 12x+3
(x–1)(x2+x+1)
A) 5
x–1+–5x+2
x2+x+1B) 5
x–1+–5
x+1+2
x–1
C) –5
x–1+5x+2
x2+x+1D) 5
x–1+2x–5
x2+x+1
7) x2–111
x4–x2–72
A) 1
x+3+1
x–3–7
x2+8B) 1
x+3–1
x–3+7
x2+8
C) 1
x+3–1
x–3–7
x2+8D) 1
x+3+1
x–3+7
x2+8
4 DecomposeP/Q,WhereQHasaPrime,RepeatedQuadraticFactor
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Writetheformofthepartialfractiondecompositionoftherationalexpression.Itisnotnecessarytosolveforthe
constants.
1) 5x+5
(x2+x+6)2
A) Ax+B
x2+x+6
+Cx+D
(x2+x+6)2B) A
x2+x+6
+Bx+C
(x2+x+6)2
C) A
x2+x+6
+B
(x2+x+6)2D) Ax+B
x2+x+6
+C
(x2+x+6)2
2) 2x+3
(x+6)(x2+x–5)2
A) A
x+6+Bx+C
x2+x–5
+Dx+E
(x2+x–5)2B) A
x+6+B
x2+x–5
+C
(x2+x–5)2
C) A
x+6+B
x2+x–5
+Cx+D
(x2+x–5)2D) A
x+6+Bx+C
x2+x–5
Writethepartialfractiondecompositionoftherationalexpression.
3) x2+2x–1
(x2+5)2
A) 1
x2+5
+2x–6
(x2+5)2B) x+1
x2+5
+2x–6
(x2+5)2C) 1
x2+5
+–x–6
(x2+5)2D) –1
x2+5
+2x–6
(x2+5)2
Page19
4) 5x3+26x–6
(x2+4)2
A) 5x
x2+4
+6x–6
(x2+4)2B) 5x+1
x2+4
+6x–6
(x2+4)2C) 5x
x2+4
+–6x–6
(x2+4)2D) 5x
x2+4
+6x+6
(x2+4)2
5) 3x3+4x2
(x2+5)2
A) 3x+4
x2+5
+–15x–20
(x2+5)2B) 3x–4
x2+5
+–15x+20
(x2+5)2C) 3x+4
x2+5
+15x+20
(x2+5)2D) 3x+4
x2+5
+15x–20
(x2+5)2
6) 4x3–6x2+14x–28
(x2+5)3
A) 4x–6
(x2+5)2+–6x+2
(x2+5)3B) x+1
x2+5
+4x–6
(x2+5)2+–6x+2
(x2+5)3
C) 4x+6
(x2+5)2+–6x–2
(x2+5)3D) x
x2+5
+4x–6
(x2+5)2+–6x+2
(x2+5)3
8.4 SystemsofNonlinearEquationsinTwoVariables
1 RecognizeSystemsofNonlinearEquationsinTwoVariables
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Decideifthesystemofequationsintwovariablesislinearornonlinear.
1) x2=2y+6
3x–y=6
A) Nonlinear B) Linear
2) y=x2–4
x2+y2=9
A) Nonlinear B) Linear
3) x=7y+8
2x–y=4
A) Linear B) Nonlinear
4) xy=–7
x+3y=6
A) Nonlinear B) Linear
5) x3+2x=y
x+4y=9
A) Nonlinear B) Linear
Page20
2 SolveNonlinearSystemsBySubstitution
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Solvethesystembythesubstitutionmethod.
1) –2x–y=–52
y=x2+4
A) {(6
,
40),(–8
,
68)} B) {(–6
,
40),(8
,
68)} C) {(6
,
32),(–8
,
60)} D) {(–6
,
40),(–8
,
68)}
2) x+y=4
y=x2–8x+16
A) {(3
,
1),(4
,
0)} B) {(–3
,
7),(–4
,
8)} C) {(4
,
0)} D) {(3
,
7),(4
,
0)}
3) y=x–2
y2=–8x
A) {(–2
,
–4)} B) {(–2
,
–4),(2
,
0)}
C) {(–2
,
–4),(–2
,
4)} D) {(–2
,
–4),(–2
,
4),(2
,
0)}
4) x2+y2=13
x+y=5
A) {(3
,
2),(2
,
3)} B) {(–3
,
2),(–2
,
3)} C) {(3
,
–2),(2
,
–3)} D) {(–3
,
–2),(–2
,
–3)}
5) xy=56
x+y=15
A) {(8
,
7),(7
,
8)} B) {(–8
,
7),(–7
,
8)} C) {(8
,
–7),(7
,
–8)} D) {(–8
,
–7),(–7
,
–8)}
6) xy=1
–16x–y=–10
A) 1
8,8 ,1
2,2 B) 8,1
8,2,1
2C) {(–8
,
8),(–2
,
2)} D) 1
2,2
7) x2=y2+39
x–y=3
A) {(8,5)} B) {(8,–5)} C) {(–8,5)} D) {(–8,–5)}
8) xy=54
x2+y2=117
A) {(6
,
9),(–6
,
–9),(9
,
6),(–9
,
–6)} B) {(6
,
9),(–6
,
–9),(6
,
–9),(–6
,
9)}
C) {(6
,
9),(9
,
6),(6
,
–9),(9
,
–6)} D) {(–6
,
–9),(–9
,
–6),(–6
,
9),(–9
,
6)}
9) x–2y=3
x2–xy=20
A) {(5,1),(–8,–11
2)} B) {(–5,–1),(8,11
2)} C) {(5,1),(–11
2,–8)} D) {(–5,–1),(11
2,8)}
10) x–y=9
(x–2)2+(y+5)2=20
A) {(6
,
–3),(0
,
–9)} B) {(–3
,
6),(–9
,
0)} C) {(6
,
–3),(4
,
–9)} D) {(–3
,
6),(–9
,
4)}
Page21
11) 6x2+12y2=300
y=x+5
A) 0,5,–20
3,–5
3B) 0,–5 ,–20
3,–5
3
C) 0,5 ,20
3,35
3D) 0,–5 ,20
3,35
3
12) y=(x+5)2+1
2x–y+10=0
A) {(–4,2)} B) {(–4,2),(4,18)} C) {(0,10),(0,26)} D) {(–5,0)}
13) 2y–x=10
x2+y2–100=0
A) {(–10
,
0),(6
,
8)} B) {(10
,
0),(–10
,
0),(6
,
8)}
C) 0,5
,
8
,
9 D) 0,5
,
0,–5
,
8
,
9
14) x2+y2=25
x–y=1
A) {(–3
,
–4),(4
,
3)} B) {(3
,
–4),(4
,
–3)} C) {(–3
,
4),(–4
,
3)} D) {(3
,
4),(4
,
3)}
15) y=–x2+13
x2+y2=25
A) {(4
,
–3),(3
,
4),(–3
,
4),(–4
,
–3)} B) {(3
,
4),(–3
,
4)}
C) {(4
,
–3),(–4
,
–3)} D) {(9
,
94),(16
,
269)}
16) x+y=2
x2+y2=4y–2
A) {(1
,
1),(–1
,
3)} B) {(1
,
1),(3
,
–1)} C) {(3
,
–1
,
(5
,
–3)} D) {(–1
,
3),(–3
,
5)}
3 SolveNonlinearSystemsByAddition
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Solvethesystembytheadditionmethod.
1) x2+y2=16
x2–y2=16
A) {(4
,
0),(–4
,
0)} B) {(0,4),(0,–4)} C) {(4
,
0)} D) {(0,4)}
2) 8x2+y2=64
8x2–y2=64
A) {(2 2,0),(–22,0)} B) {(8
,
0),(–8
,
0)}
C) {(0,22
),(0,–22)} D) {(0,8),(0,–8)}
3) x2+y2=4
4x2+25y2=100
A) {(0,2),(0,–2)} B) {(2
,
0),(–2
,
0)} C) {(0,5),(0,–5)} D) {(5
,
0),(–5
,
0)}
4) x2–y2=9
16x2+9y2=144
A) {(3
,
0),(–3
,
0)} B) {(4
,
0),(–4
,
0)} C) {(0,3),(0,–3)} D) {(0,4),(0,–4)}
Page22
5) x2+y2=125
x2–y2=–75
A) {(5
,
10),(–5
,
10),(5
,
–10),(–5
,
–10)} B) {(5
,
10),(10
,
5),(–5
,
–10),(–10
,
–5)}
C) {(5
,
–10),(5
,
10)} D) {(–5
,
–10),(–10
,
–5)}
6) 2x2–2y2=24
2x2+2y2=40
A) {(4
,
2),(–4
,
2),(4
,
–2),(–4
,
–2)} B) {(4
,
2),(2
,
4),(–4
,
–2),(–2
,
–4)}
C) {(4
,
–2),(4
,
2)} D) {(–4
,
–2),(–2
,
–4)}
7) x2–3y2=1
2x2+3y2=74
A) {(5
,
8),(–5
,
8),(5
,
–8),(–5
,
–8)} B) {(5
,
8),(–5
,
–8)}
C) {(8
,
5),(–8
,
5),(8
,
–5),(–8
,
–5)} D) {(8
,
5),(–8
,
–5)}
8) 2x2+y2=17
3x2–2y2=–6
A) {(2,3),(2,–3),(–2,3),(–2,–3)} B) {(1,3),(1,–3),(–1,3),(–1,–3)}
C) {(2,–3),(–2,3)} D) {(1,3),(–1,–3)}
9) 2x2+y2=66
x2+y2=41
A) {(5,4),(5,–4),(–5,4),(–5,–4)} B) {(4,5),(–4,5),(4,–5),(–4,–5)}
C) {(5,4),(–5,–4)} D) {(4,5),(–4,–5)}
10) x2–2y2=2
3x2+2y2=14
A) {(2,1),(2,–1),(–2,1),(–2,–1)} B) {(1,2),(–1,2),(1,–2),(–1,–2)}
C) {(2,1),(–2,–1)} D) {(–1,2),(1,–2)}
11) x2–3y2–1=0
4x2+3y2–19=0
A) {(2,1),(2,–1),(–2,1),(–2,–1)} B) {(1,2),(–1,2),(1,–2),(–1,–2)}
C) {(2,1),(–2,–1)} D) {(–1,2),(1,–2)}
12) x2–y2=5
x2+y2=15
A) {( 10,5),(–10,5),(10,–5),(–10,–5)}
B) {(0,0)}
C) {( 10,5),(–10,–5)}
D) {( 10,5),(–10,5)}
13) y2+4x2=21
y2–x2=1
A) (2,5),(2,–5),(–2,5),(–2,–5)B)(2,5),(2,–5)
C) (3,5),(3,–5),(–3,5),(–3,–5)D)(3,5),(3,–5)
Page23
14) y=x2+12
y=–x2+14
A) {(1
,
13),(–1
,
13)} B) {(1
,
13),(1
,
–13),(–1
,
13),(–1
,
–13)}
C) {(13
,
1),(13
,
–1)} D) {(1
,
13),(1
,
–13)}
15) x2+y2+6x–2y+9=0
x2–y2+6x+2y+7=0
A) {(–2
,
1),(–4
,
1)} B) {(–2
,
1),(4
,
1)} C) {(–3
,
2),(–3
,
0)} D) {(–3
,
–2),(–3
,
0)}
Solvebythemethodofyourchoice.
16) 2x2+xy–y2=3
x2+2xy+y2=3
A) 23
3,3
3,–23
3,–3
3B) 23
3,–3
3,–23
3,3
3
C) –2
3,1
3,23
3,–1
3D) –2
3,–1
3,23
3, 1
3
17) x2+y2=25
(x–6)2+y2=25
A) {(3
,
4),(3
,
–4)} B) {(3
,
4),(3
,
–4),(–3
,
4),(–3
,
–4)}
C) {(4
,
3),(4
,
–3)} D) {(4
,
3),(4
,
–3),(–4
,
3),(–4
,
–3)}
18) x2+y2=25
10x+y2=46
A) {(3
,
4),(3
,
–4)} B) {(3
,
4)}
C) {(3
,
4),(3
,
–4),(7
,
4),(7
,
–4)} D) {(3
,
4),(3
,
–4),(–3
,
4),(–3
,
–4)}
19) x3+y=0
12x2–y=0
A) {(0,0),(–12
,
1728)} B) {(0,0),(12
,
–1728)}
C) {(0,0),(–12
,
144)} D) {(–1,1),(–12
,
1728)}
4 SolveProblemsUsingSystemsofNonlinearEquations
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Letxrepresentonenumberandletyrepresenttheothernumber.Usethegivenconditionstowriteasystemofnonlinear
equations.Solvethesystemandfindthenumbers.
1) Thesumoftwonumbersis21andtheirproductis20.Findthenumbers.
A) 20and1B)
–20 and–1
C) 20and1;–20and–1D)20and–1;–20 and1
2) Thesumofthesquaresoftwonumbersis65.Thesumofthetwonumbersis–7.Findthetwonumbers.
A) –8and1B)
–8and1;–1 and8C)
–1 and8D)
–8and–1;1 and8
3) Thesumofthesquaresoftwonumbersis90.Thedifferenceofthetwonumbersis6.Findthetwonumbers.
A) –9and–3;3and9B)
–9and–3C)3and9D)
–3and9;–9 and3
4) Thesumoftwosquaresoftwonumbersis90
,
andthedifferenceoftheirsquaresis72.Findthenumbers.
A) 9and3;–9and3;9and–3;–9and–3B)9and3
C) 9and3;–9and–3D)9and3;–9 and3;9and–3
Page24
5) Thedifferencebetweenthesquaresoftwonumbersis5.Twicethesquareofthesecondnumbersubtracted
fromthesquareofthefirstnumberis1.Findthenumbers.
A) 3and2;–3and2;3and–2;–3and–2B)3and2
C) 3and2;–3and–2D)3and2;–3 and2;3and–2
Solvetheproblem.
6) Asystemfortrackingshipsindicatedthatashipliesonahyperbolicpathdescribedby6x2–y2=8.The
processisrepeatedandtheshipisfoundtolieonahyperbolicpathdescribedbyy2–2x2=8.Ifitisknown
thattheshipislocatedinthefirstquadrantofthecoordinatesystem,determineitsexactlocation.
A) (2
,
4) B) (–2
,
–4) C) (4
,
2) D) (–4
,
–2)
7) Findthedimensionsofarectanglewhoseperimeteris26 feetandwhoseareais40squarefeet.
A) 5feetby8feet B) 4feetby9 feet C) 6 feetby7 feet D) 4feetby7 feet
8) Theareaofagardenis2940squarefeet,andthelengthofitsdiagonalis91 feet.Findthedimensionsofthe
garden.
A) 35feetby84feet B) 5feetby588 feet C) 245 feetby12 feet D) 60feetby49 feet
9) Theareaofarectangularpieceofcardboardshownis893 squareinches.Thecardboardisusedtomakean
openboxbycuttinga3–inchsquarefromeachcornerandturningupthesides.Iftheboxistohaveavolume
of1599cubicinches,findthedimensionsofthecardboardthatmustbeused.
A) 19inchesby47inches B) 22 inchesby50 inches
C) 16inchesby44inches D) 13 inchesby38 inches
10) Arighttrianglehasanareaof10squareinches.Thesquareofthehypotenuseis104.Findthelengthsofthe
legsofthetriangle.Roundyouranswertothenearestinch.
A) 2inchesand10inches B) 4 inchesand100 inches
C) 1inchesand20inches D) 4 inchesand5 inches
11) Apersonatthetopofa600foottallbuildingdropsayellowball.Theheightoftheyellowballisgivenbythe
equationh=–16t2+600wherehismeasuredinfeetandtisthenumberofsecondssincetheyellowballwas
dropped.Asecondperson,inthesamebuildingbutonalowerfloorthatis180feetfromtheground,dropsa
whiteball3.5secondsaftertheyellowballwasdropped.Theheightofthewhiteballisgivenbytheequation
h=–16(t–3.5)2+180wherehismeasuredinfeetandtisthenumberofsecondssincetheyellowballwas
dropped.Findthetimethattheballsarethesamedistanceabovethegroundandfindthisdistance.
A) 5.5seconds;116feet B) 4.5 seconds;276 feet
C) 5seconds;200feet D) 6 seconds;24 feet
12) Thediagonalofthefloorofarectangularofficecubicleis2ftlongerthanthelengthofthecubicleand5ft
longerthantwicethewidth.Findthedimensionsofthecubicle.Roundtothenearesttenth,ifnecessary.
A) width=9.7ft,length=22.4ft B) width=4ft,length=11ft
C) width=2ft,length=9ft D) width=3.9ft,length=9.7ft
Page25
13) Ina1–milerace,thewinnercrossesthefinishline11 feetaheadofthesecond–placerunnerand31 feetahead
ofthethird–placerunner.Assumingthateachrunnermaintainsaconstantspeedthroughouttherace,byhow
manyfeetdoesthesecond–placerunnerbeatthethird–placerunner?(5280feetin1mile.)
A) 20.04ft B) –11.06 ft C) –20.12 ft D) 9.02 ft
8.5 SystemsofInequalities
1 GraphaLinearInequalityinTwoVariables
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Graphtheinequality.
1) x–y>–4
x
-10 10
y
10
-10
x
-10 10
y
10
-10
A)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
B)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
C)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
D)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
Page26
2) x+y<–4
x
-10 10
y
10
-10
x
-10 10
y
10
-10
A)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
B)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
C)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
D)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
Page27
3) x–y<–4
x
-10 10
y
10
-10
x
-10 10
y
10
-10
A)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
B)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
C)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
D)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
Page28
4) 5x+y≤2
x
-10 10
y
10
-10
x
-10 10
y
10
-10
A)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
B)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
C)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
D)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
Page29
5) x+5y≥3
x
-10 10
y
10
-10
x
-10 10
y
10
-10
A)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
B)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
C)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
D)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
Page30
6) –3x–4y≤12
x
-10 10
y
10
-10
x
-10 10
y
10
-10
A)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
B)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
C)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
D)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
Page31
7) 3x+4y≤12
x
-10 10
y
10
-10
x
-10 10
y
10
-10
A)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
B)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
C)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
D)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
Page32
8) –2x–4y≤–8
x
-10 10
y
10
-10
x
-10 10
y
10
-10
A)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
B)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
C)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
D)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
Page33
9) y≥x–6
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page34
10) y+5<x
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page35
11) x
3+y
2≤1
x
-10 10
y
10
-10
x
-10 10
y
10
-10
A)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
B)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
C)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
D)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
Page36
12) y<–5
4x
x
-10 10
y
10
-10
x
-10 10
y
10
-10
A)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
B)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
C)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
D)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
Page37
13) y≤5x–2
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page38
14) x>7
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page39
15) y≤7
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page40
2 GraphaNonlinearInequalityinTwoVariables
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Graphtheinequality.
1) x2+y2≤49
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page41
2) x2+y2>9
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page42
3) (x+1)2+(y–3)2>16
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page43
4) y>x2–2
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page44
5) y≤x2+3
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page45
6) y≤3x
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page46
7) y>2x
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
8) y≥log(x+8)
x
-20 -16 -12 -8 -4 4 8 12 16 20
y
5
4
3
2
1
-1
-2
-3
-4
-5
x
-20 -16 -12 -8 -4 4 8 12 16 20
y
5
4
3
2
1
-1
-2
-3
-4
-5
Page47
A)
x
–20–16–12–8–4 4 8 121620
y
5
4
3
2
1
-1
-2
-3
-4
-5
x
–20–16–12–8–4 4 8 121620
y
5
4
3
2
1
-1
-2
-3
-4
-5
B)
x
-20 -16 -12 -8 -4 4 8 12 16 20
y
5
4
3
2
1
-1
-2
-3
-4
-5
x
-20 -16 -12 -8 -4 4 8 12 16 20
y
5
4
3
2
1
-1
-2
-3
-4
-5
C)
x
–20–16–12–8–4 4 8 121620
y
5
4
3
2
1
-1
-2
-3
-4
-5
x
–20–16–12–8–4 4 8 121620
y
5
4
3
2
1
-1
-2
-3
-4
-5
D)
x
-20 -16 -12 -8 -4 4 8 12 16 20
y
5
4
3
2
1
-1
-2
-3
-4
-5
x
-20 -16 -12 -8 -4 4 8 12 16 20
y
5
4
3
2
1
-1
-2
-3
-4
-5
3 UseMathematicalModelsInvolvingLinearInequalities
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Solvetheproblem.
1) Apersonwithnomorethan$5000toinvestplanstoplacethemoneyintwoinvestments,telecommunications
andpharmaceuticals.Thetelecommunicationsinvestmentistobenomorethan5timesthepharmaceuticals
investment.Writeasystemofinequalitiestodescribethesituation.Letx=amounttobeinvestedin
telecommunicationsandy=amounttobeinvestedinpharmaceuticals.
A) x+y≤5000
x≤5y
x≥0
y≥0
B) x+y=5000
x≤5y
x≥0
y≥0
C) x+y=5000
y≥5x
x≥0
y≥0
D) x+y≤5000
5x≤y
x≥0
y≥0
2) Amanisplantingasectionofgardenwithtomatoesandcucumbers.Theavailableareaofthesectionis120
squarefeet.Hewantstheareaplantedwithtomatoestobemorethan20%oftheareaplantedwithcucumbers.
Writeasystemofinequalitiestodescribethesituation.Letx=amounttobeplantedintomatoesand
y=amounttobeplantedincucumbers.
A) x+y≤120
x>0.20y
x≥0
y≥0
B) x+y=120
x≥0.20y
x≥0
y≥0
C) x+y≤120
0.20x>y
x≥0
y≥0
D) x+y≤120
x<0.20y
x≥0
y≥0
Page48
3) Benjaminneverhasmorethan24hoursfreeduringtheweek.Heistryingtomakeaweeklyplanfordividing
hisfreetimebetweenreadingandworkingout.Hewantstospendatleast7hoursperweekreading.Writea
systemofinequalitiestodescribethesituation.Letxrepresentthenumberofhoursforreadingandyrepresent
thenumberofhoursforworkingout.
A) x+y≤24
x≥7
y≥0
B) x+y≤24
x≥7y
x≥0
y≥0
C) x+y≤24
y≥7
x≥0
D) x+y≤24
x≤7y
x≥0
y≥0
4) Avolunteerwantstocrochetbeachhatsandbabyafghansforachurchfund–raisingbazaar.Sheneeds5 hours
tomakeahatand4hourstomakeanafghanandshehas20hoursavailable.Writeaninequalitythatdescribes
thesituationandusetheinequalitytodecidewhethershecanmake0hatsand9afghansinthetimeallowed.
Letxrepresentthenumberofhatsandythenumberofafghansthatshemakes.
A) 5x+4y≤20;no B) 5x+4y≤20;yes C) 5x+4y≥20;no D) 5x+4y≥20;yes
5) Awomanworksoutbyrunningandswimming.Whensheruns,sheburns 7 caloriesperminute.Whenshe
swims,sheburns10caloriesperminute.Shewantstoburnatleast490caloriesinherworkout.Graphan
inequalitythatdescribesthesituation.Letxrepresentthenumberofminutesrunningandythenumberof
minutesswimming.Becausexandymustbepositive,limitthegraphtoquadrantIonly.
x
10 20 30 40 50 60 70
y
70
60
50
40
30
20
10
x
10 20 30 40 50 60 70
y
70
60
50
40
30
20
10
A)
x
10 20 30 40 50 60 70
y
70
60
50
40
30
20
10
x
10 20 30 40 50 60 70
y
70
60
50
40
30
20
10
B)
x
10 20 30 40 50 60 70
y
70
60
50
40
30
20
10
x
10 20 30 40 50 60 70
y
70
60
50
40
30
20
10
Page49
C)
x
10 20 30 40 50 60 70
y
70
60
50
40
30
20
10
x
10 20 30 40 50 60 70
y
70
60
50
40
30
20
10
D)
x
10 20 30 40 50 60 70
y
70
60
50
40
30
20
10
x
10 20 30 40 50 60 70
y
70
60
50
40
30
20
10
6) Theequationthatrepresentsthepropertrafficcontrolandemergencyvehicleresponseavailabilityinasmall
cityis2P+3F≤23,wherePisthenumberofpolicecarsonactivedutyandFisthenumberoffiretrucksthat
haveleftthefirehouseinresponsetoacall.Inordertocomplywithstaffinglimitations,theequation
2P+F≤17isappropriate.Thenumberofpolicecarsonactivedutyandthenumberoffiretrucksthathaveleft
thefirehouseinresponsetoacallcannotbenegative,soP≥0andF≥0.Graphtheregionssatisfyingallthe
availabilityandstaffingrequirements,usingthehorizontalaxisforPandtheverticalaxisforF.If8policecars
areonactivedutyand2firetruckshaveleftthefirehouseinresponsetoacall,arealloftherequirements
satisfied?
P
12345678910
F
10
9
8
7
6
5
4
3
2
1
P
12345678910
F
10
9
8
7
6
5
4
3
2
1
A) No
P
12345678910
F
10
9
8
7
6
5
4
3
2
1
P
12345678910
F
10
9
8
7
6
5
4
3
2
1
B) Yes
P
12345678910
F
10
9
8
7
6
5
4
3
2
1
P
12345678910
F
10
9
8
7
6
5
4
3
2
1
Page50
C) No
P
12345678910
F
10
9
8
7
6
5
4
3
2
1
P
12345678910
F
10
9
8
7
6
5
4
3
2
1
D) Yes
P
12345678910
F
10
9
8
7
6
5
4
3
2
1
P
12345678910
F
10
9
8
7
6
5
4
3
2
1
7) Abakeryplanstomarketamixedassortmentofitstwomostpopularcookies,ChocolateChipandToffee
Chunk.Themarketinganalystproposesthatthenewassortmentbeconstrainedbytheinequality3C+4T≤31,
whereCisthenumberofChocolateChipcookiesandTisthenumberofToffeeChunkcookies.Thesales
analystsuggeststhattheassortmentshouldbeconstrainedbytheinequality5C+2T≤33.Thenumberofeach
typeofcookiecannotbenegative,soC≥0andT≥0.Graphtheregionsatisfyingalltherequirementsforthe
assortmentusingCasthehorizontalaxisandTastheverticalaxis.Doesthecombinationof6ChocolateChip
cookiesand3ToffeeChunkcookiessatisfyalloftherequirements?
C
12345678910
T
10
9
8
7
6
5
4
3
2
1
C
12345678910
T
10
9
8
7
6
5
4
3
2
1
A) No
C
12345678910
T
10
9
8
7
6
5
4
3
2
1
C
12345678910
T
10
9
8
7
6
5
4
3
2
1
B) Yes
C
12345678910
T
10
9
8
7
6
5
4
3
2
1
C
12345678910
T
10
9
8
7
6
5
4
3
2
1
Page51
C) No
C
12345678910
T
10
9
8
7
6
5
4
3
2
1
C
12345678910
T
10
9
8
7
6
5
4
3
2
1
D) Yes
C
12345678910
T
10
9
8
7
6
5
4
3
2
1
C
12345678910
T
10
9
8
7
6
5
4
3
2
1
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
8) TheJillsonʹshaveupto$75,000toinvest.Theydecidethattheywanttohaveatleast$40,000investedinstable
bondsyielding6%andthatnomorethan$20,000shouldbeinvestedinmorevolatilebondsyielding12%.
(a)Usingxtodenotetheamountofmoneyinvestedinthestablebondsandytheamountinvestedinthemore
volatilebonds,writeasystemoflinearinequalitiesthatdescribethepossibleamountsofeachinvestment.
(b)Graphthesystemofinequalities.
x
y
x
y
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
9) Theliquidportionofadietistoprovideatleast300calories,36unitsofvitaminA,and90unitsofvitaminC
daily.AcupofdietarydrinkXprovides60calories,12unitsofvitaminA,and10unitsofvitaminC.Acupof
dietarydrinkYprovides60calories,6unitsofvitaminA,and30unitsofvitaminC.Setupasystemoflinear
inequalitiesthatdescribestheminimumdailyrequirementsforcaloriesandvitamins.Letx=numberofcups
ofdietarydrinkX,andy=numberofcupsofdietarydrinkY.Writealltheconstraintsasasystemoflinear
inequalities.
A) 60x+60y≥300
12x+6y≥36
10x+30y≥90
x≥0
y≥0
B) 60x+60y>300
12x+6y>36
10x+30y>90
x>0
y>0
C) 60x+60y≥300
12x+6y>36
10x+30y≥90
D) 60x+60y≤300
12x+6y≤36
10x+30y≤90
x≥0
y≥0
Page52
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
10) Acoffeestorehasavailable75poundsofAgradecoffeeand120poundsofBgradecoffee.Thesewillbe
blendedinto1poundpackagesasfollows:aneconomyblendthatcontains4ouncesofAgradecoffeeand12
ouncesofBgradecoffeeandasuperiorblendthatcontains8ouncesofAgradecoffeeand8ouncesofBgrade
coffee.Usingxtodenotethenumberofpackagesoftheeconomyblendandytodenotethenumberof
packagesofthesuperiorblend,writeasystemoflinearinequalitiesthatdescribesthepossiblenumberof
packagesofeachblend.Graphthesystemofinequalities.
x
y
x
y
Page53
4 GraphaSystemofInequalities
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Graphthesolutionsetofthesystemofinequalitiesorindicatethatthesystemhasnosolution.
1) 3x–y≤3
x+2y≥–6
x
-10 -8 -6 -4 -2 2 4 6 8 10
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
-10 -8 -6 -4 -2 2 4 6 8 10
y
10
8
6
4
2
-2
-4
-6
-8
-10
A)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
B)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
C)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
D)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
Page54
2) y<–x+5
y>2x–3
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
–20 -10 10 20
y
20
10
-10
-20
x
–20 -10 10 20
y
20
10
-10
-20
D)
x
–20 -10 10 20
y
20
10
-10
-20
x
–20 -10 10 20
y
20
10
-10
-20
Page55
3) x+2y≥2
x–y≤0
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
A)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
B)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
C)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
D)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
Page56
4) 1≤y<8
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
A)
x
–10–8-6-4-2 2 4 6 810
y
12
10
8
6
4
2
-2
-4
-6
-8
-10
-12
x
–10–8-6-4-2 2 4 6 810
y
12
10
8
6
4
2
-2
-4
-6
-8
-10
-12
B)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
-12
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
-12
C)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
-12
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
-12
D)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
Page57
5) –x+7y<7
x≥4
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page58
6) y<x+1
2x+7y>28
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page59
7) y>–5
x≥–3
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
A)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
B)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
C)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
D)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
Page60
8) –3x+y>3
–3x+y<–1
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
A) nosolution B)
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
C)
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
D)
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
Page61
9) 2x+y<4
2x+y>1
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
A)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
B)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
C)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
D) ∅
Page62
10) y>x2
10x+2y≤20
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page63
11) x2+y2≤100
–6x+5y≤–30
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page64
12) y≥3x
y≤8
x
-10 10
y
10
-10
x
-10 10
y
10
-10
A)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
B)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
C)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
D)
x
-10 10
y
10
-10
x
-10 10
y
10
-10
Page65
13) x2+y2≤25
x2+y2≥4
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
A)
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
B) nosolution
C)
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
D)
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
x
–8–6–4–2 2468
y
6
4
2
-2
-4
-6
14) x2+y2≤64
y–x2>0
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page66
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
D)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
15) x2+y2≤36
y>3x
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page67
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
D)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
16) x2+y2≤16
x+y>1
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page68
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
–10–8-6-4-2 2 4 6 810
y
12
10
8
6
4
2
-2
-4
-6
-8
-10
-12
x
–10–8-6-4-2 2 4 6 810
y
12
10
8
6
4
2
-2
-4
-6
-8
-10
-12
D)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
17) x2+y2≤100
5x+5y≤25
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page69
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page70
18) (x+5)2+(y+2)2>16
(x+5)2+(y+2)2<36
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
A)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
B)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
C)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
D)
x
-10 -5 5 10
y
10
5
-5
-10
x
-10 -5 5 10
y
10
5
-5
-10
Page71
19) x+2y≥6
x>–2
y≤6
x
–10–8–6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8–6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
A)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
B)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
C)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
D)
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
x
–10–8-6-4-2 2 4 6 810
y
10
8
6
4
2
-2
-4
-6
-8
-10
Page72
20) x+y≤9
y≥8x–3
x≥0
y≥0
x
-5 5
y
10
5
-5
-10
x
-5 5
y
10
5
-5
-10
A)
x
-5 5
y
10
5
-5
-10
x
-5 5
y
10
5
-5
-10
B)
x
-5 5
y
10
5
-5
-10
x
-5 5
y
10
5
-5
-10
C)
x
-5 5
y
10
5
-5
-10
x
-5 5
y
10
5
-5
-10
D)
x
-5 5
y
10
5
-5
-10
x
-5 5
y
10
5
-5
-10
Page73
21) 2x+3y≥6
x–y≤3
y≤2
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
A)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
B)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
C)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
D)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
Page74
22) y≥2x–4
x+2y≤7
x≥–2
y≤1
x
-8 -4 4 8
y
8
4
-4
-8
x
-8 -4 4 8
y
8
4
-4
-8
A)
x
-8 -4 4 8
y
8
4
-4
-8
x
-8 -4 4 8
y
8
4
-4
-8
B)
x
-8 -4 4 8
y
8
4
-4
-8
x
-8 -4 4 8
y
8
4
-4
-8
C)
x
-8 -4 4 8
y
8
4
-4
-8
x
-8 -4 4 8
y
8
4
-4
-8
D)
x
-8 -4 4 8
y
8
4
-4
-8
x
-8 -4 4 8
y
8
4
-4
-8
Page75
23) y≥2x–4
x+2y≤7
y≥–2
x≤1
x
-8 -4 4 8
y
8
4
-4
-8
x
-8 -4 4 8
y
8
4
-4
-8
A)
x
-8 -4 4 8
y
8
4
-4
-8
x
-8 -4 4 8
y
8
4
-4
-8
B)
x
-8 -4 4 8
y
8
4
-4
-8
x
-8 -4 4 8
y
8
4
-4
-8
C)
x
-8 -4 4 8
y
8
4
-4
-8
x
-8 -4 4 8
y
8
4
-4
-8
D)
x
-8 -4 4 8
y
8
4
-4
-8
x
-8 -4 4 8
y
8
4
-4
-8
Page76
24) x≥0
y≥0
2x+2y≤4
2x+y≤5
x
-4 -2 2 4
y
4
2
-2
-4
x
-4 -2 2 4
y
4
2
-2
-4
A)
x
-4 -2 2 4
y
4
2
-2
-4
x
-4 -2 2 4
y
4
2
-2
-4
B)
x
-4 -2 2 4
y
4
2
-2
-4
x
-4 -2 2 4
y
4
2
-2
-4
C)
x
-4 -2 2 4
y
4
2
-2
-4
x
-4 -2 2 4
y
4
2
-2
-4
D)
x
-4 -2 2 4
y
4
2
-2
-4
x
-4 -2 2 4
y
4
2
-2
-4
Page77
25) y≥1
2≤x≤6
x–2y≥–2
x+y≤6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
A)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
B)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
C)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
D)
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
x
-6 -4 -2 2 4 6
y
6
4
2
-2
-4
-6
Page78
8.6 LinearProgramming
1 WriteanObjectiveFunctionDescribingaQuantityThatMustbeMaximizedorMinimized
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Solvetheproblem.
1) Asteelcompanyproducestwotypesofmachinedies,partAandpartB.Thecompanymakesa$3.00 profiton
eachpartAthatitproducesanda$5.00profitoneachpartBthatitproduces.Letx=thenumberofpartA
producedinaweekandy=thenumberofpartBproducedinaweek.Writetheobjectivefunctionthat
describesthetotalweeklyprofit.
A) z=3x+5y B) z=5x+3y
C) z=8(x+y) D) z=3(x–5)+5(y–3)
2) Adietitianneedstopurchasefoodforpatients.Shecanpurchaseanounceofchickenfor$0.35andanounceof
potatoesfor$0.03.Letx=thenumberofouncesofchickenandy=thenumberofouncesofpotatoes
purchasedperpatient.Writetheobjectivefunctionthatdescribesthetotalcostperpatientpermeal.
A) z=0.35x+0.03y B) z=0.03x+0.35y C) z=35x+3y D) z=3y+35y
2 UseInequalitiestoDescribeLimitationsinaSituation
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Solvetheproblem.
1) Asteelcompanyproducestwotypesofmachinedies,partAandpartBandisboundbythefollowing
constraints:
·PartArequires1hourofcastingtimeand10hoursoffiringtime.
·PartBrequires4hoursofcastingtimeand3hoursoffiringtime.
·Themaximumnumberofhoursperweekavailableforcastingandfiringare100and70,respectively.
·Thecosttothecompanyis$0.75perpartAand$3.00perpartB.Totalweeklycostscannotexceed$45.00.
Letx=thenumberofpartAproducedinaweekandy=thenumberofpartBproducedinaweek.Writea
systemofthreeinequalitiesthatdescribestheseconstraints.
A)
x+4y ≤100
10x +3y ≤70
0.75x +3y ≤45
B)
x+10y ≤100
4x +3y ≤70
0.75x +3y ≤45
C)
x+10y ≥100
4x +3y ≥70
0.75x +3y ≤45
D)
x+4y ≤100
10x +3y ≤70
3x +0.75y ≤45
2) Adietitianneedstopurchasefoodforpatients.Shecanpurchaseanounceofchickenfor$0.25andanounceof
potatoesfor$0.02.Thedieticianisboundbythefollowingconstraints.
·Eachounceofchickencontains13gramsofproteinand24gramsofcarbohydrates.
·Eachounceofpotatoescontains5gramsofproteinand35gramsofcarbohydrates.
·Theminimumdailyrequirementsforthepatientsunderthedietitianʹscareare45gramsofproteinand58
gramsofcarbohydrates.
Letx=thenumberofouncesofchickenandy=thenumberofouncesofpotatoespurchasedperpatient.Write
asystemofinequalitiesthatdescribestheseconstraints.
A)
13x +5y ≥45
24x +35y ≥58
B)
13x +24y ≥45
5x +35y ≥58
C)
13x +5y ≥58
24x +35y ≥45
D)
13x +24x ≥45
5y +35y ≥58
Page79
3) Mrs.Whitewantstocrochethatsandafghansforachurchfundraisingbazaar.Sheneeds6hourstomakeahat
and2hourstomakeanafghan,andshehasnomorethan48hoursavailable.Shehasmaterialfornomorethan
14items,andshewantstomakeatleasttwoafghans.Letx=thenumberofhatsshemakesandy=thenumber
ofafghansshemakes.Writeasystemofinequalitiesthatdescribestheseconstraints.
A) 6x+2y≤48
x+y≤14
y≥2
B) 6x+2y≤48
x+y≤14
x≥2
C) 2x+6y≤48
x+y≤14
x≤2
D) 6x+2y≥48
x+y≤14
y≥2
4) Anofficemanagerisbuyingusedfilingcabinets.Smallfilecabinetscost$5 eachandlargefilecabinetscost$11
each,andthemanagercannotspendmorethan$101onfilecabinets.Asmallcabinettakesup5squarefeetof
floorspaceandalargecabinettakesup10squarefeet,andtheofficehasnomorethan95squarefeetoffloor
spaceavailableforfilecabinets.Themanagermustbuyatleast5filecabinetsinordertogetfreedelivery.Letx
=thenumberofsmallfilecabinetsboughtandy=thenumberoflargefilecabinetsbought.Writeasystemof
inequalitiesthatdescribestheseconstraints.
A) 5x+11y≤101
5x+10y≤95
x+y≥5
B) 5x+11y≤101
10x+5y≤95
x≥5
C) 5x+11y≤101
5x+10y≤95
x+y≤5
D) 5x+11y≤101
5x+10y≤95
y≥5
3 UseLinearProgrammingtoSolveProblems
MULTIPLECHOICE.Choosetheonealternativethatbestcompletesthestatementoranswersthequestion.
Findthemaximumorminimumvalueofthegivenobjectivefunctionofalinearprogrammingproblem.Thefigure
illustratesthegraphofthefeasiblepoints.
1) ObjectiveFunction:z=3x+4y
Findmaximumandminimum.
x
y
(0, 8) (8, 8)
(8, 2)
(
2
,
0
)
(0, 2)
x
y
(0, 8) (8, 8)
(8, 2)
(
2
,
0
)
(0, 2)
A) maximumvalue:56;minimumvalue:6 B) maximumvalue:56;minimumvalue:8
C) maximumvalue:32;minimumvalue:6 D) maximumvalue:32;minimumvalue:8
Page80
Findthemaximumorminimumvalueofthegivenobjectivefunctionofalinearprogrammingproblem.Thefigure
illustratesthegraphoffeasiblepoints.
2) ObjectiveFunction:z=x+7y
Findmaximum.
A) maximum:37 B) maximum:24 C) maximum:18 D) maximum:30
3) ObjectiveFunction:z=–x–5y
Findmaximum.
A) maximum:–14 B) maximum:–18 C) maximum:–27 D) maximum:–22
4) ObjectiveFunction:z=9x+10y
Findminimum.
A) minimum:56 B) minimum:57 C) minimum:68 D) nominimum
5) ObjectiveFunction:z=x+8y+8
Findminimum.
A) minimum:28 B) minimum:50 C) minimum:36 D) nominimum
6) ObjectiveFunction:z=–6x–y
Findmaximum.
A) maximum:–17 B) maximum:–21 C) maximum:–26 D) nomaximum
Anobjectivefunctionandasystemoflinearinequalitiesrepresentingconstraintsaregiven.Graphthesystemof
inequalitiesrepresentingtheconstraints.Findthevalueoftheobjectivefunctionateachcornerofthegraphedregion.
Usethesevaluestodeterminethemaximumvalueoftheobjectivefunctionandthevaluesofxandyforwhichthe
maximumoccurs.
7) ObjectiveFunction z=18x+6y
Constraints 0≤x≤10
0≤y≤5
3x+2y≥6
A) Maximum:210;at(10,5) B) Maximum:180;at(10,0)
C) Maximum:30;at(0,5) D) Maximum:18;at(0,3)
8) ObjectiveFunction z=6x+7y
Constraints x≥0
y≥0
2x+3y≤12
2x+y≤8
A) Maximum32;at(3,2) B) Maximum32;at(2,3)
C) Maximum52;at(4,4) D) Maximum24;at(4,0)
Page81
9) ObjectiveFunction z=3x+5y
Constraints x≥0
y≥0
2x+y≤15
x–3y≥–3
A) Maximum33;at(6,3) B) Maximum75;at(0,15)
C) Maximum22.5;at(7.5,0) D) Maximum38;at(6,4)
10) ObjectiveFunction z=17x–19y
Constraints 0≤x≤5
0≤y≤8
4x+5y≤30
4x+3y≤20
A) Maximum:85;at(5,0) B) Maximum:0;at(0,0)
C) Maximum:–73.75;at(1.25,5) D) Maximum:–114;at(0,6)
11) ObjectiveFunction z=7x+9y
Constraints x≥0
0≤y≤5
2x+3y≥12
2x+3y≤20
A) Maximum:70;at(10,0) B) Maximum:59;at(2,5)
C) Maximum:42;at(6,0) D) Maximum:–28;at(4,0)
12) ObjectiveFunction z=7x–3y
Constraints x≥0
0≤y≤3
x–y≤2
x+2y≤8
A) Maximum:22;at(4
,
2) B) Maximum:14;at(2
,
0)
C) Maximum:5;at(2,3) D) Maximum:–9;at(0,3)
13) ObjectiveFunction z=7x+6y
Constraints x≥0
y≥0
3x+y≤21
x+y≤10
x+2y≥12
A) Maximum65.5;at(5.5,4.5) B) Maximum60;at(6,3)
C) Maximum68;at(8,2) D) Maximum66;at(6,4)
Solvetheproblem.
14) Twokindsofcratedcargo,AandB,aretobeshippedbytruck.Theweightandvolumeofeachtypearegiven
inthefollowingtable:
AB
Volume 50cubicfeet 10cubicfeet
Weight 200pounds 360pounds
Theshippingcompanycharges$75percrateforcargoAand$100percrateforcargoB.Thetruckhasa
maximumloadlimitof7,200poundsand1,000cubicfeet.Howmanyofeachtypeofcargoshouldbeshipped
tomaximizeprofitfortheshippingcompany?
A) 18cratesofcargoAand10cratesofcargoBB)20cratesofcargoAand0cratesofcargoB
C) 0cratesofcargoAand20cratesofcargoBD)10cratesofcargoAand18cratesofcargoB
Page82
15) Avineyardproducestwospecialwines,awhiteandared.Abottleofthewhitewinerequires14poundsof
grapesand1hourofprocessingtime.Abottleofredwinerequires25poundsofgrapesand2hoursof
processingtime.Thevineyardhasonhand2,198poundsofgrapesandcanallot160hoursofprocessingtime
totheproductionofthesewines.Abottleofthewhitewinesellsfor$11.00,whileabottleoftheredwinesells
for$20.00.Howmanybottlesofeachtypeshouldthevineyardproduceinordertomaximizegrosssales?
A) 132bottlesofwhiteand14bottlesofred B) 14bottlesofwhiteand132bottlesofred
C) 76bottlesofwhiteand42bottlesofred D) 42bottlesofwhiteand59bottlesofred
16) Acandycompanyhas120poundsofcashewsand160 poundsofpeanutswhichtheycombineintotwo
differentmixes.Thedeluxemixhashalfcashewsandhalfpeanutsandsellsfor$7perpound.Theeconomy
mixhasonethirdcashewsandtwothirdspeanutsandsellsfor$4.80perpound.Howmanypoundsofeach
mixshouldbepreparedformaximumrevenue?
A) 160poundsofdeluxeand120poundsofeconomy
B) 240poundsofdeluxeand80poundsofeconomy
C) 80poundsofdeluxeand40poundsofeconomy
D) 120poundsofdeluxeand0poundsofeconomy
17) Adoctorhastoldasickpatienttotakevitaminpills.Thepatientneedsatleast32unitsofvitaminA,atleast7
unitsofvitaminB,andatleast27unitsofvitaminC.Theredvitaminpillscost10¢eachandcontain8unitsof
A,1unitofB,and3unitsofC.Thebluevitaminpillscost20¢eachandcontain4unitsofA,1unitofB,and5
unitsofC.Howmanypillsshouldthepatienttakeeachdaytominimizecosts?
A) 4redand3blue B) 3redand4 blue C) 7 redand0blue D) 5redand2 blue
18) Mrs.Whitewantstocrochethatsandafghansforachurchfundraisingbazaar.Sheneeds7hourstomakeahat
and2hourstomakeanafghan,andshehasnomorethan53hoursavailable.Shehasmaterialfornomorethan
14itemsandnomorethan10afghans.Thebazaarwillsellthehatsfor$18eachandtheafghansfor$5each.
Howmanyofeachshouldshemaketomaximizetheincomeforthebazaar?Whatisthemaximumincome?
A) 5hatsand9afghans;$135 B) 9 hatsand5 afghans;$187
C) 10hatsand4afghans;$200 D) 7 hatsand7 afghans;$161
19) Anofficemanagerisbuyingusedfilingcabinets.Eachsmallfilecabinetcosts$5
,
takesup7squarefeetoffloor
space,andholds10cubicfeetoffiles.Eachlargefilecabinetcosts$12,takesup10squarefeetoffloorspace,
andholds14cubicfeetoffiles.Thetotalcostcannotexceed$112,andtheofficehasnomorethan116square
feetoffloorspaceavailableforthecabinets.Howmanyofeachfilecabinetshouldthemanagerbuyto
maximizestoragecapacity?Whatisthemaximumstoragecapacity?
A) 8smallfilecabinetsand6largefilecabinets;164 cubicfeet
B) 6smallfilecabinetsand8largefilecabinets;192 cubicfeet
C) 0smallfilecabinetsand14largefilecabinets;196 cubicfeet
D) 14smallfilecabinetsand0largefilecabinets;140 cubicfeet
SHORTANSWER.Writethewordorphrasethatbestcompleteseachstatementoranswersthequestion.
20) Yourcomputersupplystoresellstwotypesoflaserprinters.Thefirsttype,A,hasacostof$86andyoumakea
$45profitoneachone.Thesecondtype,B,hasacostof$130andyoumakea$35profitoneachone.You
expecttosellatleast100laserprintersthismonthandyouneedtomakeatleast$3850profitonthem.How
manyofwhattypeofprintershouldyouorderifyouwanttominimizeyourcost?
21) TheJillsonʹshaveupto$75,000toinvest.Theydecidethattheywanttohaveatleast$25,000investedinstable
bondsyielding6%andthatnomorethan$45,000shouldbeinvestedinmorevolatilebondsyielding12%.How
muchshouldtheyinvestineachtypeofbondtomaximizeincomeiftheamountinthemorevolatilebond
shouldnotexceedtheamountinthemorestablebond?Whatisthemaximumincome?
Page83
22) TheFiedlerfamilyhasupto$130,000toinvest.Theydecidethattheywanttohaveatleast$40,000investedin
stablebondsyielding5.5%andthatnomorethan$60,000shouldbeinvestedinmorevolatilebondsyielding
11%.Howmuchshouldtheyinvestineachtypeofbondtomaximizeincomeiftheamountinthestablebond
shouldnotexceedtheamountinthemorevolatilebond?Whatisthemaximumincome?
23) EricʹsCarpentrymanufacturestwotypesofbookshelvesthatare4feettalland3feetwide,abasicmodelanda
deluxemodel.Eachbasicbookshelfrequires1.5hoursforassemblyand1hourforfinishing;eachdeluxemodel
requires2.5hoursforassemblyand1hourforfinishing.Twoassemblersandonefinisherareemployedbythe
company,andeachworks40hoursperweek.Ericcansellmorebasicmodelsthandeluxemodels,sohewants
thenumberofbasicmodelsproducedtobe50%morethanthenumberofdeluxemodelsproduced.Ifhe
makes$50profitonthebasicmodelsand$65profitonthedeluxemodels,howmanyshouldhemaketo
maximizetheprofit?Whatisthemaximumprofit?
24)
J
oelyʹsTeaShop,astorethatspecializesinteablends,hasavailable45poundsofAgradeteaand70poundsof
Bgradetea.Thesewillbeblendedinto1poundpackagesasfollows:Abreakfastblendthatcontainsonethird
ofapoundofAgradeteaandtwothirdsofapoundofBgradeteaandanafternoonteathatcontainsonehalf
poundofAgradeteaandonehalfpoundofBgradetea.IfJoelymakesaprofitof$1.50oneachpoundofthe
breakfastblendand$2.00profitoneachpoundoftheafternoonblend,howmanypoundsofeachblendshould
shemaketomaximizeprofits?Whatisthemaximumprofit?
25) Anartistiscreatingamosaicthatcannotbelargerthanthespaceallottedwhichis4feettalland6feetwide.
Themosaicmustbeatleast3feettalland5feetwide.Thetilesinthemosaichavewordswrittenonthemand
theartistwantsthewordstoallbehorizontalinthefinalmosaic.Thewordtilescomeintwosizes:Thesmaller
tilesare4inchestalland4incheswide,whilethelargetilesare6inchestalland12incheswide.Ifthesmall
tilescost$3.50eachandthelargertilescost$4.50each,howmanyofeachshouldbeusedtominimizethecost?
Whatistheminimumcost?
Page84
Ch.8 SystemsofEquationsandInequalities
AnswerKey
8.1 SystemsofLinearEquationsinTwoVariables
1 DecideWhetheranOrderedPairisaSolutionofaLinearSystem
2 SolveLinearSystemsbySubstitution
3 SolveLinearSystemsbyAddition
4 IdentifySystemsThatDoNotHaveExactlyOneOrdered –PairSolution
15) A
5 SolveProblemsUsingSystemsofLinearEquations
Page85
8.2 SystemsofLinearEquationsinThreeVariables
1 VerifytheSolutionofaSystemofLinearEquationsinThreeVariables
2 SolveSystemsofLinearEquationsinThreeVariables
Page86
3 SolveProblemsUsingSystemsinThreeVariables
8.3 PartialFractions
1 DecomposeP/Q,WhereQHasOnlyDistinctLinearFactors
2 DecomposeP/Q,WhereQHasRepeatedLinearFactors
3 DecomposeP/Q,WhereQHasaNonrepeatedPrimeQuadraticFactor
4 DecomposeP/Q,WhereQHasaPrime,RepeatedQuadraticFactor
Page87
8.4 SystemsofNonlinearEquationsinTwoVariables
1 RecognizeSystemsofNonlinearEquationsinTwoVariables
2 SolveNonlinearSystemsBySubstitution
3 SolveNonlinearSystemsByAddition
4 SolveProblemsUsingSystemsofNonlinearEquations
Page88
8.5 SystemsofInequalities
1 GraphaLinearInequalityinTwoVariables
2 GraphaNonlinearInequalityinTwoVariables
8) A
3 UseMathematicalModelsInvolvingLinearInequalities
Page89
4 GraphaSystemofInequalities
Page90
8.6 LinearProgramming
1 WriteanObjectiveFunctionDescribingaQuantityThatMustbeMaximizedorMinimized
2 UseInequalitiestoDescribeLimitationsinaSituation
3 UseLinearProgrammingtoSolveProblems
Page91