SOLUTION: Caitlin recently rode her bicycle to visit her friend who lives 12 miles away. On her way there, her average speed was 10 miles per hour faster than on her way home. If Caitlin spe

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Caitlin recently rode her bicycle to visit her friend who lives 12 miles away. On her way there, her average speed was 10 miles per hour faster than on her way home. If Caitlin spe      Log On


   



Question 1054732: Caitlin recently rode her bicycle to visit her friend who lives 12 miles away. On her way there, her average speed was 10 miles per hour faster than on her way home. If Caitlin spent a total of 1 hour bicycling, find the two rates.
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
12/r + 12/(r+10) = 1
Multiply thru by r(r+10)
12(r+10) + 12r = r(r+10)
12r + 120 + 12r = r^2 + 10r
r^2 - 14r - 120 = 0
(r + 6)(r-20) = 0
r = highlight%2820mph%29 and r+10 = highlight%2830mph%29