Correct. Substitute 6 for p and $\displaystyle-{3}\usepackage{cmbright}\Huge\$ for q: $\displaystyle{4}{{\left({6}\right)}}^{{2}}-{{\left(-{3}\right)}}^{{2}}={4}{\left({36}\right)}-{9}={144}-{9}={135}\usepackage{cmbright}\Huge\$