Question

Megan's commute to work includes an 8-mile drive and a 21-mile train ride. This expression can be used to find the total time it takes Megan toget to work, where x is her average driving speed in miles/hour.

Answer 1

The time is:

$time=\frac{distance}{average\text{ }speed}$

Then, the average speed of the train is represented by x + 20.

If x = 45, then:

$\begin{gathered} time=\frac{8}{45}+\frac{21}{45+20} \\ time=0.5\text{ }hour \end{gathered}$

Answer:

1) x + 20

2) 0.5 hour