Answer
$\dfrac{1}{\sqrt[6]{3,125x^5y^{5}}}$
Work Step by Step
Using the laws of exponents, the given expression, $
(5xy)^{-5/6}
,$ is equivalent to
\begin{array}{l}\require{cancel}
\dfrac{1}{(5xy)^{5/6}}
.\end{array}
Using $a^{m/n}=\sqrt[n]{a^m}=(\sqrt[n]{a})^m$, the expression, $
\dfrac{1}{(5xy)^{5/6}}
,$ simplifies to
\begin{array}{l}\require{cancel}
\dfrac{1}{\sqrt[6]{(5xy)^{5}}}
\\\\=
\dfrac{1}{\sqrt[6]{5^5x^5y^{5}}}
\\\\=
\dfrac{1}{\sqrt[6]{3,125x^5y^{5}}}
.\end{array}