recall that minus * minus = positive, so (-3)² is really (-3)(-3), which gives us a positive 3*3 or 9.
[tex] \bf -(3)^2-(3)^2~~ = ~~ (-3)^2(-3)^2~\hspace{5em}
\begin{array}{|ccc|ll}
\cline{1-3}
&&\\-(3)^2-(3)^2 &=& (-3)^2(-3)^2\\&&\\
-9-9&&(9)(9)\\&&\\
-18&\ne&81\\
&&\\
\cline{1-3}
\end{array} [/tex]