Answer
$\dfrac{1}{\sqrt[10]{128x^7y^7}}
$
Work Step by Step
RECALL:
(i) $a^{-\frac{m}{n}}=\dfrac{1}{a^{\frac{m}{n}}}$
(ii) $a^{\frac{m}{n}}=\sqrt[n]{a^m}$
(iii) $(ab)^m=a^mb^m$
Use the rules above to obtain:
$=\dfrac{1}{(2xy)^{\frac{7}{10}}}
\\=\dfrac{1}{\sqrt[10]{(2xy)^7}}
\\=\dfrac{1}{\sqrt[10]{2^7x^7y^7}}
\\=\dfrac{1}{\sqrt[10]{128x^7y^7}}
$
