College Algebra, Chapter 2, 2.4, Section 2.4, Problem 74

Jan and Krix leave Detroit at 2:00 PM and drive at a constant speed, traveling west. They pass Ann Arbor, $40 mi$ from Detroit at 2:50 PM.

a.) Express the distance traveled in terms of the time elapsed?

b.) Draw the graph of the equation in part (a).

c.) What is the slope of this line? What does it represent?



a.) Recall that $\displaystyle V = \frac{d}{t}$, so $d = Vt$


$
\begin{equation}
\begin{aligned}

d =& \frac{40 mi}{50 min} (t)
\\
\\
d =& \frac{4}{5} t

\end{aligned}
\end{equation}
$


b.)








c.) The slope of the line is $\displaystyle \frac{4}{5}$. It represents the constant speed that Jan and Krix exhibits.