Use the power property: $\displaystyle{\log}_{{b}}{{M}}^{{n}}={n}\cdot{\log}_{{b}}{M}\usepackage{cmbright}\Huge\$

This simplifies $\displaystyle{\log}_{{{2}}}{{32}}^{{x}}\usepackage{cmbright}\Huge\$ to $\displaystyle{x}\cdot{\log}_{{{2}}}{32}\usepackage{cmbright}\Huge\$ .

Because $\displaystyle{32}={{2}}^{{5}}\usepackage{cmbright}\Huge\$ , $\displaystyle{\log}_{{{2}}}{32}\usepackage{cmbright}\Huge\$ simplifies to 5. So $\displaystyle{\log}_{{{2}}}{{32}}^{{x}}={x}\cdot{5}={5}{x}\usepackage{cmbright}\Huge\$ .