$\displaystyle{\left({x}+{11}\right)}{\left({x}-{11}\right)}={{x}}^{{2}}-{{11}}^{{2}}={{x}}^{{2}}-{121}\usepackage{cmbright}\Huge\$ , which is not equal to $\displaystyle{{x}}^{{2}}+{22}{x}+{121}\usepackage{cmbright}\Huge\$ .