Answer
$\dfrac{5}{\sqrt{15}}$
Work Step by Step
Rationalizing the numerator of $
\sqrt{\dfrac{5}{3}}
$ results to
\begin{array}{l}
\sqrt{\dfrac{5}{3}}
\cdot
\sqrt{\dfrac{5}{5}}
\\\\=
\sqrt{\dfrac{25}{15}}
\\\\=
\dfrac{5}{\sqrt{15}}
.\end{array}