If $\displaystyle{h}=\usepackage{cmbright}\Huge\$ the number of hours, then she is charged $\displaystyle{8}{h}\usepackage{cmbright}\Huge\$ dollars plus the $52. So $\displaystyle{8}{h}+{52}={144}\usepackage{cmbright}\Huge\$ . Subtract 52 from both sides: $\displaystyle{8}{h}={92}\usepackage{cmbright}\Huge\$ . Divide both sides by 8: $\displaystyle{h}={11.5}\usepackage{cmbright}\Huge\$ . She cannot rent the car for a fraction of an hour, so she can rent it for at most 11 hours.