Question

To solve this system of equations by addition (elimination), what could you multiply each equation by to cancel out the x-variable?

A: 2x−3y=−6B: −5x−9y=15


A. Multiply A by 2 and B by 5
B. Multiply A by -5 and B by 2
C. Multiply A by 5 and B by -2
D. Multiply A by 5 and B by 2

Answer 1

You will multiply A by 5 and B by 2.

A: 5(2x - 3y) = -6(5)
B: 2(-5x - 9y) = 15(2)

Simplify.

A: 10x - 15y = -30

B: -10x - 18y = 30

When you add down:

10x + (-10x) = 0 <--- Eliminates the x-value.

(-15y) + (-18y) = -33y

(-30) + 30 = 0

Your ending solution will be -33y = 0

Hope this helps! :)