SOLUTION: the smith and jones families plan a train from cedar city to lake powelll. the smith family makes the 168 mile trip at a speed that is 8 miles per hour faster than the jones family

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Question 1170345: the smith and jones families plan a train from cedar city to lake powelll. the smith family makes the 168 mile trip at a speed that is 8 miles per hour faster than the jones family. the jones family is pulling the boat and takes half and hour longer to make the trip. what are the speeds of the 2 families?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
                SPEED       TIME          DIST.

smith            r+8       168/(r+8)      168

jones            r         168/r          168

difference                 1/2

168%2Fr-168%2F%28r%2B8%29=1%2F2-------simplify and solve.
.
.
r%5E2%2B8r-2688=0
r=%28-8%2Bsqrt%2864%2B4%2A2688%29%29%2F2
highlight%28r=48%29
and
highlight%28r%2B8=56%29