Answer
$-4a^{5}$
Work Step by Step
Using the properties of radicals, the given expression, $
-\dfrac{2}{7}\sqrt[]{196a^{10}}
,$ simplifies to
\begin{array}{l}\require{cancel}
-\dfrac{2}{7}\sqrt[]{(14a^{5})^2}
\\\\=
-\dfrac{2}{7}\cdot14a^{5}
\\\\=
-\dfrac{2}{\cancel{7}}\cdot\cancel{7}\cdot2a^{5}
\\\\=
-4a^{5}
.\end{array}
Note that all of the variables are assumed to represent non-negative real numbers.
