-2x + y = 7
2x + y = -9
First, add the equations together...
2y = -2
Divide by 2 on both sides...
y = -1
Now, plug in -1 for y to find x...
2x + (-1) = -9
Add one on both sides...
2x = -8
Divide by 2 on both sides...
x = -4
Your answers are...
x = -4
y = -1
Hope this helps :)
