$[0/1\mathrm{.}25$ Points$]$

Evaluate the following integral by first rewriting it as an equivalent integral with the order of integration reversed.

${\displaystyle \underset{0}{\overset{4}{}}}{\displaystyle \underset{\frac{x}{2}}{\overset{2}{}}}3\sqrt[\phantom{2}]{y^2+5}dydx$