A-22 Answers
70. x1=no. o
ecturers
re
20x1+25x2=k2 salaries
College 2: 3 lecturers hired and 6 instructors hired
Exercises 4.7
–0.2 0.9
0.4 1.2
12. X=cx1
x2d=c12.4
7.2 d 13. X=cx1
x2d=c16.4
9.2 d 14. X=cx1
x2d=c25.2
15.6 d
–0.2 –0.1 0.9 § 18. £1.6 0.4 0.4
0.38 0.22 1.22 §
20. Agriculture: $42 billion; building: $23.9 billion; energy: $23.1 billion
21.
0.6 1.6
;
46
24.
1.75 0.25
0.5 1.5
;
31.25
37.5
25. £1.58 0.24 0.58
0.4 1.2 0.4
18
23.
–
is singular; X does not exist.
27. (A) Agriculture: $80 million; manufacturing: $64 million. (B) The final
demand for agriculture increases to $54 million and the final demand for
between 0 and 1, inclusive. 35. Coal: $28 billion; steel: $26 billion
36. Transportation: $22 billion; manufacturing: $37 billion 37. Agriculture:
41. Year 1: agriculture: $65 billion; energy: $83 billion; labor: $71 billion;
manufacturing: $88 billion
42. Year 1: agriculture: $50 billion; energy: $68 billion; labor: $44 billion;
manufacturing: $88 billion
Year 2: agriculture: $61 billion; energy: $82 billion; labor: $57 billion; manu-
facturing: $102 billion
1. x=4, y=4 (4.1) 2. x=4, y=4 (4.1) 3. (A) Not in reduced form;
R14R2 (B) Not in reduced form;
R24R2 (C) Reduced form (D) Not
in reduced form;
–1
R2+R1SR1 (4.3) 4. (A) 2 *5, 3 *2
(4.2, 4.4) 5. (A) x1=8, x2=2 (B) x1=–15.5, x2=23.5 (4.6) 6. c33
d (4.4)
67. x1=
res
ent’s
onus
x2=execut
ve v
ce-
res
ent’s
onus
vice-president: $37,400; assistant vice-president: $27,900
68. (A) x1=president’s bonus (B) No
x2=executive vice president’s bonus
x1+0.03x2+0.03x
+0.03x4+0.03x
=
0,000
associate vice president: $37,000; assistant vice president:
$27,600; sales manager: $18,300
69. (A) x1=no. o
ounces o
m
x A
Diet 3: 150 oz mix A and 500 oz mix B
(B) No
7. Not defined (4.4) 8. c–30
1–1d (4.4) 9.
74
(4.4)
10. Not defined (4.4) 11.
5
(4.4) 12. c23
46
d (4.4)
–23
18. x1=9,x2=–11; x1=16, x2=–19; x1=–2, x2=4 (4.6)
19. Not defined (4.4) 20. c10 –8
46
d (4.4) 21.
–28
86
(4.4)
25. £–
1–11
20–
2§ (4.5)
(B) x1=–5t–12, x2=3t+7, x3=t for t any
x2=t+3, x3=t for t any real number (4.3)
x2=2, x3=–2 (4.6) 28. The system has an infinite no. of solutions for