Incorrect. To simplify this expression, work from the inside out. Start by simplifying the expressions $\displaystyle{{\left({{x}}^{{-{{3}}}}{{y}}^{{5}}\right)}}^{{-{{2}}}}\usepackage{cmbright}\Huge\$ and $\displaystyle{{\left({{x}}^{{2}}{{y}}^{{-{{3}}}}\right)}}^{{-{{4}}}}\usepackage{cmbright}\Huge\$ , then multiply them, and then raise that entire quantity to the power of 3. Remember to use the exponent rules: $\displaystyle{{\left({{x}}^{{n}}\right)}}^{{m}}={{x}}^{{{n}{m}}}\usepackage{cmbright}\Huge\$ and $\displaystyle{{x}}^{{n}}{{x}}^{{m}}={{x}}^{{{n}+{m}}}\usepackage{cmbright}\Huge\$ .