You may have partially used the laws of exponents to simplify. However, you incorrectly divided the constant by 4. The expression can first be rewritten as: $\displaystyle{{\left({16}{{f}}^{{4}}{{g}}^{{2}}{{h}}^{{8}}\right)}}^{{\frac{{1}}{{4}}}}\usepackage{cmbright}\Huge\$

The second step is to write the expression as: $\displaystyle{{16}}^{{\frac{{1}}{{4}}}}\cdot{{\left({{f}}^{{4}}\right)}}^{{\frac{{1}}{{4}}}}\cdot{{\left({{g}}^{{2}}\right)}}^{{\frac{{1}}{{4}}}}\cdot{{\left({{h}}^{{8}}\right)}}^{{\frac{{1}}{{4}}}}\usepackage{cmbright}\Huge\$