Incorrect. You have the following system of equations:

$\displaystyle{e}={10}{h}\usepackage{cmbright}\Huge\$

$\displaystyle{204}-{e}={12}{\left({19}-{h}\right)}\usepackage{cmbright}\Huge\$

Try using the substitution method to solve for h: $\displaystyle{204}-{\left({10}{h}\right)}={12}{\left({19}-{h}\right)}\usepackage{cmbright}\Huge\$

This equation becomes: $\displaystyle{204}-{10}{h}={228}-{12}{h}\usepackage{cmbright}\Huge\$

Solve this equation for h, the amount of hours the team spent washing cars. Then find $\displaystyle{19}-{h}\usepackage{cmbright}\Huge\$ , the amount of hours the team spent mowing lawns.