SOLUTION
To get how much Vince is paid for one hour of work, we simply find the slope of the graph.
Slope is given as
![\begin{gathered} s=\text{ }(y2-y1)/(x2-x1) \\ \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/sz7odibtkttppqgmxakvsuu52a1puas058.png)
Let's consider two points on the line
x1 at 20 hours, which gives y1 at $180
x2 t 40 hours, which gives y2 at $360
Slope becomes
![\begin{gathered} s\text{ = }(y2-y1)/(x2-x1) \\ \\ s\text{ = }(360-180)/(40-20) \\ \\ s\text{ = }(180)/(20) \\ \\ s\text{ = }9 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/zrkej1qffpwqe703t7w7f3zlrv7bze5s6q.png)
That means Vince is paid $9 at every hour of work.