During the first part of a trip, a canoeist travels 69 miles at a certain speed. The canoeist traveled 23 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?
1st part 69m @ X+5mph
2nd part 23m @ X
so,69m/x+5 + 23m/x = 2hours
69/x+5 + 23/x = 2
LCD ==> 69(x)+ 23(x+5)= 2x(x+5)
69x+23x+115=2x^2+10x
92x+115=2x^2+10x
0=2x^2-82x-115
wont factor, use quadratic formula
x=(-b�}�ã(b^2-4ac))/2a
x=-(-82)�}�ã(-82)^2 -(4)(2)(-115) / 2(2)
+82 = 39.55mph, -82 = negative number
so, 23 miles @ 39.55mph and 69 miles
@ (39.55 + 5mph =) 44.55mph