Correct. $\displaystyle{{\left({a}-{b}\right)}}^{{2}}={{a}}^{{2}}-{2}{a}{b}+{{b}}^{{2}}\usepackage{cmbright}\Huge\$ . In this case $\displaystyle{a}={4}{x}\usepackage{cmbright}\Huge\$ and $\displaystyle{b}={3}\usepackage{cmbright}\Huge\$ , so $\displaystyle{{\left({4}{x}-{3}\right)}}^{{2}}={{\left({4}{x}\right)}}^{{2}}-{2}{\left({4}{x}\right)}{\left({3}\right)}+{{3}}^{{2}}={16}{{x}}^{{2}}-{24}{x}+{9}\usepackage{cmbright}\Huge\$ .