Question

Collin wants to solve this system of equations. Which number can he multiply the first equation by so that when the two equations are added together, the x term is eliminated?

1/2x + 1/4y = 5
2x + 3/8y = 5

A. -4
B. -2
C. 2
D. 4

Answer 1

A.-4

Explanation:

I just took the test

Answer 2

if u multiply the first equation by -4, u get -2x - y = -20

and when u add the 2 equations..
-2x - y = -20
2x + 3/8y = 5
-----------------
0 - 5/8y = -15.....u notice that the x terms r eliminated.