What is the solution to this system of equations?

x - 2y = 15

2x + 4y = - 18

Use the subtraction method.

2 (x - 2y = 15) multiply top equation by 2 so we can subtract

2x - 4y = 30

2x + 4y = - 18 (subtracted, we get 4x = 12 ... divide by 4 ... x = 3)

place the value for X into an original equation and solve for Y.

2 (3) + 4y = - 18

6 + 4y = - 18

-6 - 6

4y = - 24 (divide by 4)

y = - 6 Solution ... (3, - 6)