You may have chosen this answer because $\displaystyle{96}={3}\cdot{32}\usepackage{cmbright}\Huge\$ . However, $\displaystyle\sqrt{{96}}=\sqrt{{{3}\cdot{32}}}=\sqrt{{3}}\cdot\sqrt{{32}}\usepackage{cmbright}\Huge\$ , using the rule $\displaystyle\sqrt{{{a}{b}}}=\sqrt{{{a}}}\cdot\sqrt{{{b}}}\usepackage{cmbright}\Huge\$ . Since $\displaystyle\sqrt{{3}}\usepackage{cmbright}\Huge\$ is not equal to 3, $\displaystyle\sqrt{{{3}}}\cdot\sqrt{{{32}}}\ne{3}\sqrt{{32}}\usepackage{cmbright}\Huge\$ .