Having a difficult time simplifying the following expression:

-y^{2}/ (1+y)^{2 -----> -}y^{2}/ (1+2y+y^{2})

---->y^{2}* (1+2y+y^{2})^{-1 [how would I distribute across the parenthesis considering the -1 exponent?] Any pointers would be appreciated. }