y=9/7x
1) Solving that equation 9x +y = 8y for y is simply to rearrange algebraically and then solve for.
9x +y = 8y Subtract 8y from both sides
y-8y = -9x
-7y =-9x Divide both sides by -7
y= 9/7x
2) Then, the solution is y=9/7x there's no way to reduce it beyond that point.