It appears that you were thinking of the product rule, but you used the wrong order of operations. You must apply exponents before multiplication. So you must simplify $\displaystyle{{\left({{w}}^{{3}}\right)}}^{{4}}\usepackage{cmbright}\Huge\$ and $\displaystyle{{\left({{w}}^{{5}}\right)}}^{{2}}\usepackage{cmbright}\Huge\$ first. Use the power rule: $\displaystyle{{\left({{x}}^{{a}}\right)}}^{{b}}={{x}}^{{{a}\cdot{b}}}\usepackage{cmbright}\Huge\$ . Then to complete the problem use the product rule: $\displaystyle{{x}}^{{a}}\cdot{{x}}^{{b}}={{x}}^{{{a}+{b}}}\usepackage{cmbright}\Huge\$ .