distance to the store = distance from the store
Also; 9 hr = time getting there + time getting back
[tex]
\frac{25 \ mi}{1 \ hr}*t= \frac{20 \ mi}{1 \ hr} * (9 -t )[/tex]
25t = 180 - 20t
45t = 180
t = 4 hr
Since I specified that "t" was the time driven at 25 mph this is the time getting there. 9 hr - 4 hr = 5 hr is the time getting home (driving at 20 mph)
