I have a quick question. When I did this I got my derivative but one question is asking when Rearranging this, we get
8y7y' = ???? i don't know
We now have d/ dx [x5 + y8] = 5x4 + 8y7y' = d/ dx [9] = 0.
Solving for y', we conclude that the derivative is
y' = -5x^4/8y^7