Incorrect. Remember to cube the monomial $\displaystyle{2}{{x}}^{{2}}{y}\usepackage{cmbright}\Huge\$ before multiplying it by $\displaystyle\frac{{1}}{{{4}{{x}}^{{3}}{y}}}\usepackage{cmbright}\Huge\$ . You can also think about the problem like this: $\displaystyle{\left({2}{{x}}^{{2}}{y}\right)}{\left({2}{{x}}^{{2}}{y}\right)}{\left({2}{{x}}^{{2}}{y}\right)}\frac{{1}}{{{\left({4}{{x}}^{{3}}{y}\right)}}}\usepackage{cmbright}\Huge\$ . Does that help you to simplify the expression?