Incorrect. Remember to cube the monomial $\displaystyle{4}{{x}}^{{5}}{y}\usepackage{cmbright}\Huge\$ and to square the monomial $\displaystyle\frac{{1}}{{4}}{x}{{y}}^{{3}}\usepackage{cmbright}\Huge\$ before multiplying the two terms. You can also think about this expression like this: $\displaystyle{\left({4}{{x}}^{{5}}{y}\right)}{\left({4}{{x}}^{{5}}{y}\right)}{\left({4}{{x}}^{{5}}{y}\right)}{\left(\frac{{1}}{{4}}{x}{{y}}^{{3}}\right)}{\left(\frac{{1}}{{4}}{x}{{y}}^{{3}}\right)}\usepackage{cmbright}\Huge\$ . Does that help you simplify this expression?