Question 142830
 x-8y=37
3x+8y=-17

When we have systems of equations, we can subtract one equation from the other (and likewise add them). The explanation of why that is is fairly advanced, but I will show you the easiest way to do this problem:
 x-8y=37
3x+8y=-17
ADD the equations

x+3x-8y+8y=37-17
4x=20
x=5

Now, plug x=5 into the first equation to get y
5-8y=37
-32=8y
-4=y

solution set x=5, y=-4.
If it is unclear what I did (make sure you look carefully), send me an E-mail at enabla@gmail.com.