Question

Dave works two jobs.He works at the grocery store making $12 per hour and works at the car wash making $14 per hour.If he worked a total of 30 hours and made $396,how many hours did he work at the car wash?Set up the 2 equations and then solve

Answer 1

let x be the hours at grocery store and y at carwash. We get that

`\begin{gathered} \begin{cases}x+y=30 \\ 12x+14y=396\end{cases}\rightarrow\begin{cases}x=30-y \\ 12x+14y=396\end{cases}\rightarrow \\ 12(30-y)+14y=396\rightarrow360-12y+14y=396\rightarrow \\ 2y=396-360=36 \\ y=18\rightarrow x=12 \end{gathered}`