Respuesta :

(y^-5) / (y^-2)
Flip fraction and get rid of the negative from the exponents (you can do that!)
(y^2) / (y^5)
(y * y) / (y * y * y * y * y)
Cancel y's
1 / (y * y * y)
1 / (y^3)

That's your answer.
Have an awesome day! :)