Incorrect. Use the quotient property to first rewrite $\displaystyle{\log}_{{{5}}}\frac{{y}}{{{{125}}^{{x}}}}\usepackage{cmbright}\Huge\$ as $\displaystyle{\log}_{{{5}}}{y}-{\log}_{{{5}}}{\left({{125}}^{{x}}\right)}\usepackage{cmbright}\Huge\$ . Then use the power property. The correct answer is $\displaystyle{3}{x}\usepackage{cmbright}\Huge\$ .