Question 80779
x – 2y = 8
x + y = -1

Multiply the second equation by 2 to get both y's opposite of eachother
2(x + y) = -1(2)
2x + 2y = -2

Now plug in your first equation
x - 2y = 8
2x + 2y = -2

3x = 6
x = 2