I got $\displaystyle \displaystyle -\frac{y^7}{9x^5}$, assuming you wanted to simplify $\displaystyle \displaystyle \frac{-(3)^5(x^9)(y^{-20})}{(3^7)(x^{14})(y^{-27})(y^0)}$
yes that is the problem. Prove It the negative is outside the 3. Sorry I didnt know about LaTex. I get the x and the y part, but I'm not understand the other part.