Answer
$\dfrac{\sqrt{10}}{5}$
Work Step by Step
Rationalize the denominator by multiplying $\sqrt{5}$ to both the numerator and the denominator to obtain:
$=\dfrac{\sqrt{2} \cdot \sqrt{5} }{\sqrt{5} \cdot \sqrt{5}}
\\=\dfrac{\sqrt{2(5)}}{5}
\\=\dfrac{\sqrt{10}}{5}$