Complete the indicated row operation.
Replace R2 in 2611 1
7–712 12
-1 –3–6 0 with 5R2.
2611 1
12 –217 17
-1 –3–6 0
230 11 1
7–35 12 12
-1 –15 –6 0
2611 1
35 –35 60 60
-1 –3–6 0
10 30 55 5
35 –35 60 60
-5 –15 –30 0
Translate to a system of three equations, then solve.
A company makes 3 types of cable. Cable A requires 3 black, 3 white, and 2 red wires. B requires 1
black, 2 white, and 1 red. C requires 2 black, 1 white, and 2 red. They used 100 black, 110 white and
90 red wires. How many of each cable were made?
20 cable A, 30 cable B, 10 cable C
10 cable A, 30 cable B, 93 cable C
10 cable A, 30 cable B, 20 cable C
10 cable A, 103 cable B, 20 cable C
Translate the problem to a system of equations, then solve using matrices.
A grain dealer sold to one customer 5 bushels of wheat, 2 of corn, and 3 of rye, for $20.60; to
another, 2 of wheat, 3 of corn, and 5 of rye, for $28.40; and to a third, 3 of wheat, 5 of corn, and 2 of
rye, for $22.10. What was the price per bushel for corn?
Translate to a system of two equations, then solve.
How many liters of a 30% alcohol solution must be mixed with 40 liters of a 70% solution to get a
50% solution?
There were 420 people at a play. The admission price was $3 for adults and $1 for children. The
admission receipts were $780. How many adults and how many children attended?
180 adults and 240 children
240 adults and 180 children
195 adults and 225 children
120 adults and 300 children
Solve the system using substitution.
9x – 5y = 25
7x – 2y = 10
Solve by transforming the augmented matrix into row echelon form.
x + y + z = -3
x – y + 4z = 16
3x + y + z = -5