Question

2. Joshua saves $50 every two weeks he works. Thetoatal amount of money Joshua saves isproportional to the number of weeks he works.Which of the following graphs shows the amountof money, y, Joshua saves when he works for xweeks?

Answer 1

Let:

x = Number of weeks

y = Total amount of money

Let:

$\begin{gathered} (x1,y1)=(0,0) \\ (x2,y2)=(2,50) \\ the_{\text{ }}slope_{\text{ }}is\colon \\ m=\frac{y2-y1}{x2-x1}=\frac{50-0}{2-0}=\frac{50}{2}=25 \\ using_{\text{ }}the_{\text{ }}point-slope_{\text{ }}equation \\ y-y1=m(x-x1) \\ y-0=25(x-0) \\ y=25x \end{gathered}$

Therefore, the only graph which satisfies the equation is graph C