the correct answer is x=1 and y=-2
to solve for x and y, you can either substitute equations or add or subtract the equation.
for my explanation, I will subtract equations.
to start, you must look at the xs and ys to find similarities. since they both have 8y, we can easily subtract the equations to cancel the y for now and find x
x+8y=-15. x+8y=-15
-(7x+8y=-9. = -7x-8y=9
when you subtract the equations you get
-6x=-6
dividing each side by -6 to get the x by itself will give you
x=1
then, solve for y by substituting the 1 in the x stop of either equation
I will be substituting the x in the first equation
1+8y=-15
8y=-16
y=8
both equations should give you the same answer
to check, substitute the x and y in the other equation
7(1)+8(-2)=-9
7-16=-9
-9=-9
so x=1 and y=-2