Incorrect. The final table should look like this:

Earnings =
Rate
*
Time

Washing cars
e
=
16
*
h

Yardwork
$\displaystyle{424}-{e}\usepackage{cmbright}\Huge\$
=
20
*
$\displaystyle{23}-{h}\usepackage{cmbright}\Huge\$

Try using the substitution method to solve for h: $\displaystyle{424}-{\left({16}{h}\right)}={20}{\left({23}-{h}\right)}\usepackage{cmbright}\Huge\$

Solve this equation for h, the amount of hours the team spent washing cars. Then find $\displaystyle{23}-{h}\usepackage{cmbright}\Huge\$ , the amount of hours the team spent doing yardwork.

	Earnings	=	Rate	*	Time
Washing cars	e	=	16	*	h
Yardwork	$\displaystyle{424}-{e}\usepackage{cmbright}\Huge\$	=	20	*	$\displaystyle{23}-{h}\usepackage{cmbright}\Huge\$