Question 53099
distance(d)=rate(r)*time(t)
Trip to the meeting:
time:10
rate:r
distance:10r
-------------
Return Trip:
time:9
rate:r+8
distance:9(r+8)
The distance to the meeting is equal to the return distance, so we can set the two disatnces equal to each other and solve for r.
10r=9(r+8)
10r=9r+72
10r-9r=-9r+9r+72
r=72 mph
The trip to =r=72 mph
Return trip= r+8=72+8=80mph
(They didn't ask, but for fun, you can now find the distance of the trip to be 720 miles. Think about it.)