SOLUTION: I need help with the following problem please. A car is taking a trip driving to James Town that is 80 miles away. On the return trip the car is driving 10 miles/hour slower on

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Question 26966: I need help with the following problem please.
A car is taking a trip driving to James Town that is 80 miles away. On the return trip the car is driving 10 miles/hour slower on the way back. It took 20 minutes longer to get back . How fast was the car traveling on the trip to James Town and how fast was it traveling on the return trip.

Answer by Paul(988) About Me  (Show Source):
You can put this solution on YOUR website!
On going he ws travelling at x mph
On way back he was travelling at x-10mph.
Total distance = 80
20 minutes = 1/3h

80%2Fx%2B80%2F%28x-10%29=1%2F3
80%28%28x%29-%28x-10%29%29=1%28x%29%28x-10%29%2F3
800=%28x%5E2-10x%29%2F3
2400=x%5E2-10x
x%5E2-10x-2400=0
Use quadratic formula and solve you get
x=5sqrt%2897%2B1%29
x=54.2 (rounded)

54.2-10=44.2

Hence, he speed going was 54.2mph and his speed returning was 44.2mph.
Paul.