A person traveled 9 hours to a meeting The return trip took

A person traveled 9 hours to a meeting. The return trip took only 8 hours because the speed was 10 miles per hour faster. What was the speed both ways?

Solution

A person traveled 9 hours to a meeting. The return trip took only 8 hours because the speed was 10 miles per hour faster. What was the speed both ways?
D distance = R rate in miles per hour * T time in hours
R * 9 = (R+10) * 8
9R=8R+80
R=80
rate one way is 80 miles per hour
rate on way back is 90 miles per hour
(just my opinion, laughing out loud, but that person is bound to get a speeding ticket)
my verification:
80*9=720
90*8=720