Use the formula $\displaystyle{d}={r}{t}\usepackage{cmbright}\Huge\$ to represent both legs of the journey. Her outgoing trip can be represented by $\displaystyle{d}={r}\cdot{1.5}\usepackage{cmbright}\Huge\$ , and her incoming trip can be represented by $\displaystyle{d}={\left({r}+{2}\right)}{\left({1.25}\right)}\usepackage{cmbright}\Huge\$ , since her rate was 2 mph faster on the return trip.