Answer
$12m^{2}$
Work Step by Step
(Multiply 4 and 3 since they're outside of the radical)
$4\times3=12$
(Multiply the numbers inside of the radical)
$\frac{1}{5}\times5=1$
$m^{3}\times m=m^{4}$
(Simplify $m^{4}$)
$\sqrt m^{4}=m^{2}$
$12m^{2}$