Ans: $x^{11}y^{20}$
$\begin{array}{cl}
& \dfrac{(x^8y^7)^2}{x^5y^{-6}} \\
= & \dfrac{x^{16}y^{14}}{x^5y^{-6}} \\
= & x^{16-5}y^{14-(-6)} \\
= & x^{11}y^{20}
\end{array}$
$\begin{array}{cl}
& \dfrac{(x^8y^7)^2}{x^5y^{-6}} \\
= & \dfrac{x^{16}y^{14}}{x^5y^{-6}} \\
= & x^{16-5}y^{14-(-6)} \\
= & x^{11}y^{20}
\end{array}$
