Correct. If you start with an expression of the form $\displaystyle{{x}}^{{2}}+{b}{x}\usepackage{cmbright}\Huge\$ , you need to add the number $\displaystyle{{\left(\frac{{b}}{{2}}\right)}}^{{2}}\usepackage{cmbright}\Huge\$ to complete the square. In this expression, $\displaystyle{b}=-{22}\usepackage{cmbright}\Huge\$ , so:

$\displaystyle{{\left(\frac{{b}}{{2}}\right)}}^{{2}}={{\left(\frac{{-{22}}}{{2}}\right)}}^{{2}}={{\left(-{11}\right)}}^{{2}}={121}\usepackage{cmbright}\Huge\$