SOLUTION: During the first part of a trip, a canoeist travels 75 miles at a certain speed. The canoeist travels 12 miles on the second part of the trip at a speed 5 mph slower. The total t
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Question 506573: During the first part of a trip, a canoeist travels 75 miles at a certain speed. The canoeist travels 12 miles on the second part of the trip at a speed 5 mph slower. The total time for the trip is 2 hrs. What was the speed on each part of the trip? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! During the first part of a trip, a canoeist travels 75 miles at a certain speed.
The canoeist travels 12 miles on the second part of the trip at a speed 5 mph slower.
The total time for the trip is 2 hrs.
What was the speed on each part of the trip?
:
Let s = the certain speed of the 1st part of the trip
then
(s-5) = his speed on the 2nd part of the trip
:
Write a time equation, time = dist/speed
: + = 2 hrs
multiply by s(s-5), results:
75(s-5) + 12s = 2s(s-5)
:
75s - 375 + 12s = 2s^2 - 10s
87s - 375 = 2s^2 - 10s
;
Arrange as a quadratic equation
2s^2 - 10s - 87s + 375 = 0
2s^2 - 97s + 375 = 0
:
Solve this using the quadratic formula, a=2, b=-97, c=375
only one solution will be reasonable.
