Question

In order to solve the system of equations below, Harvey multiplies each equation by a constant to eliminate the x

terms.
7x+ 3y = 5
2x+5v=-11
What are the resulting equations?

Answer 1

A) 14x + 6y = 10

-14x - 35y = 77

Explanation:

multiple the first equation by 2 and the second equation by -7

2( 7x + 3y = 5)

-7( 2x + 5y = -11)

14x + 6y = 10

-14x - 35y = 77

Answer 2

14x + 6y = 10

14x + 35y = -77

Explanation:

Multiply the top one by 2

14x + 6y = 10

Multiply the bottom one by 7

14x + 35y = -77

His next step is to subtract. You could have done this by multiplying the top one by -2

-14x - 6y = - 10

14x + 35y = -77 Now all you need do is add. The question now becomes what do you do? What answer do you give? I think the expected answer is the top two equations, but if I was actually doing the problem, I'd use the bottom 2.