Add these together.
You get -15y=-45
So y=3
Now plug in to first equation.
8x-8(3)=-16
8x-24=-16
8x=8 so x=1
Check both values in second equation.
-8(1)-7(3)=
-8-21=-29
It works...so x=1, y=3
The answer to the question is 0.6
The answer to your question is 9
