Question 318875
During the first part of a trip a canoeist travels 49 miles at a certain speed.
 The canoeist travels 6 miles on the second part of the trip at a speed of 5mph slower. 
The total time for the trip is 3 hrs.
 What was the speed on each part of the trip?
:
Let s = speed traveled the 1st 49 mi
then
(s-5) = speed on the last 6 mi
:
Write a time equation: time = dist/speed
:
time for 49 mi + time for 6 mi = 3 hrs
{{{49/s}}} + {{{6/((s-5))}}} = 3
multiply by s(s-5), results:
49(s-5) + 6s = 3s(s-5}
49s - 245 + 6s = 3s^2 - 15s
55s - 245 = 3s^2 - 15s
0 = 3s^2 - 15s - 55s + 245
3s^2 - 70s + 245 = 0
:
Solve for s using the quadratic formula; only one solution will make sense