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7 votes
7 votes
Question 10 of 10

In order to solve the following system of equations by subtraction, which of
the following could you do before subtracting the equations so that one
variable will be eliminated when you subtract them?
4x - 2y=7
3x - 3y=15
A. Multiply the top equation by 15 and the bottom equation by 7.
B. Multiply the top equation by-3 and the bottom equation by 2.
O C. Multiply the top equation by 3 and the bottom equation by 4.

Can someone help me

User Adam Lamers
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2.6k points

1 Answer

17 votes
17 votes

Answer:

B. Multiply the top equation by-3 and the bottom equation by 2.

Explanation:

-3(4x-2y=7)

2(3x-3y=15)

-12x + 6y= -21

6x - 6y = 30

6y and -6y both cancel each other out which gives us 0 when -3 is multiplied by the top and the bottom is multiplied by 2, which gives us the answer B.

User JonWarnerNet
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3.0k points