Logaritmer

$$\begin{gathered} \left\{\begin{array}{l}lg{x}^{-2}+lg{y}^4=4\\ lgx-lgy=3\end{array} \right. \\ -2lgx+4lgy=3 \\ lgx - lgy=12 \\ 4(lgx-lgy)=4*3 \\ 4lgx-4lgy=12 \\ -2lgx+4lgy=4 \\ 2lgx=16 \\ lgx=8 \\ lgx-lgy=3 \\ 8-lgy=3 \\ lgy=5 \end{gathered}$$

Har jag gjort rätt