Answer
$4$
Work Step by Step
$\bf{\text{Solution Outline:}}$
To evaluate the given expression, $
\dfrac{2a}{5}
,$ substitute the given value $a=10.$
$\bf{\text{Solution Details:}}$
Substituting $a=10,$ the given expression evaluates to
\begin{array}{l}\require{cancel}
\dfrac{2a}{5}
\\\\=
\dfrac{2(10)}{5}
\\\\=
\dfrac{20}{5}
\\\\=
4
.\end{array}