Correct. To simplify the expression, find the cube root of 125 and the cube root of $\displaystyle{{m}}^{{3}}\usepackage{cmbright}\Huge\$ .

$\displaystyle{\sqrt[{{3}}]{{{125}{{m}}^{{3}}}}}={\sqrt[{{3}}]{{{5}\cdot{5}\cdot{5}\cdot{{m}}^{{3}}}}}={\sqrt[{{3}}]{{{{5}}^{{3}}\cdot{{m}}^{{3}}}}}={\sqrt[{{3}}]{{{{5}}^{{3}}}}}\cdot{\sqrt[{{3}}]{{{{m}}^{{3}}}}}={5}{m}\usepackage{cmbright}\Huge\$