Apply the exponent 3 to each factor within the parentheses: $\displaystyle{{\left(-{2}\right)}}^{{3}}{{\left({{g}}^{{5}}\right)}}^{{3}}{{\left({{h}}^{{2}}\right)}}^{{3}}\usepackage{cmbright}\Huge\$

Simplify, using the Power Rule: $\displaystyle-{8}{{g}}^{{{5}\cdot{3}}}{{h}}^{{{2}\cdot{3}}}=-{8}{{g}}^{{15}}{{h}}^{{6}}\usepackage{cmbright}\Huge\$