(x^z-9)(x^z-36)=0
(=)\(\left[ \begin{array}{l}x^{z}-9=0\\x^{z}-36-0\end{array} \right.\) 9=)\(\left[ \begin{array}{l}x^{z}=9\\x=36\end{array} \right.\) (=)\(\left[ \begin{array}{l}x^{z}=3²\\x^{z}=6²\end{array} \right.\) (=)\(\left[ \begin{array}{l}x=±3;z=2\\x=±6;z=2\end{array} \right.\)