What is the solution to this system of equations?

x - 2y = 15

2x + 4y = - 18

A. x = 1, y = - 6

B. x = 1, y = - 7

C. x = 3, y = - 6

E. x = 3, y = - 7

Use the property of substitution to solve:

2 (x - 2y = 15) ... 2x - 4y = 30

2x + 4y = - 18

subtract ... 4x = 12

divide by 4 x = 3 place into original equation 3 - 2y = 15

-2y = 12

y = - 6

(3, - 6)