SOLUTION: Naoki bikes 40 miles to Hillsboro. The return trip is at 6 mph slower. Total travel time for round trip is 14 hours. Find her speed on each part of the trip.

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Naoki bikes 40 miles to Hillsboro. The return trip is at 6 mph slower. Total travel time for round trip is 14 hours. Find her speed on each part of the trip.      Log On


   

Question 997009: Naoki bikes 40 miles to Hillsboro. The return trip is at 6 mph slower. Total travel time for round trip is 14 hours. Find her speed on each part of the trip.
Found 2 solutions by Alan3354, josgarithmetic:
Answer by Alan3354(69443) About Me  (Show Source):
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
system%28k=6%2Ch=14%2Cd=40%29

Unknown variables are t, j, r. 
            speed       time     distance
TO           r           t        d
FROM         r-k         j        d
Total                    h

The basic rate formula allows to find expressions for each of t and j. 
            speed       time        distance
TO           r           d/r         d
FROM         r-k         d/(r-k)     d
Total                    h

Notice the total time sum and the indicated equation highlight%28d%2Fr%2Bd%2F%28r-k%29=h%29. Solve the equation for r. Once the formula is simplified, substitute the given values and evaluate r.