Correct. Notice that when binomials with different numbers, such as $\displaystyle{\left({4}{x}+{6}\right)}{\left({x}+{6}\right)}\usepackage{cmbright}\Huge\$ , are multiplied together, they do not produce special products. Special products are only generated in the cases of $\displaystyle{{\left({a}-{b}\right)}}^{{2}}\usepackage{cmbright}\Huge\$ , $\displaystyle{{\left({a}+{b}\right)}}^{{2}}\usepackage{cmbright}\Huge\$ , and $\displaystyle{\left({a}+{b}\right)}{\left({a}-{b}\right)}\usepackage{cmbright}\Huge\$ .