Correct. 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}\usepackage{cmbright}\Huge\$ , and her incoming trip can be represented by $\displaystyle{d}={\left({r}-{3}\right)}{\left({1.5}\right)}\usepackage{cmbright}\Huge\$ , since her rate was 3 mph slower on the return trip.