Answer
$\dfrac{y^{16}}{25x^{5}}$
Work Step by Step
Using laws of exponents, then,
\begin{array}{l}
\dfrac{5^{-2}x^{-3}y^{11}}{x^2y^{-5}}
\\\\=
\dfrac{x^{-3-2}y^{11-(-5)}}{5^{2}}
\\\\=
\dfrac{x^{-5}y^{16}}{25}
\\\\=
\dfrac{y^{16}}{25x^{5}}
.\end{array}
