Question

What is the solution to this system of equations?
x-2y=15
2x + 4y=-18​

Answer 1

x = 3; y = -6

Explanation:

x - 2y = 15

2x + 4y = -18​

Multiply both sides of the first equation by 2. Write the second equation below it, and add the two equations.

2x - 4y = 30

(+) 2x + 4y = -18

---------------------------

4x = 12

4x/4 = 12/4

x = 3

Now we substitute 3 for x in the first equation and solve for y.

x - 2y = 15

3 - 2y = 15

-2y = 12

y = -6

Answer: x = 3; y = -6