What is ...

x+8y=-15

7x+8y=-9

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

Y = -15/8 - x

y=-9/8 - 7x