SOLUTION: Steve traveled 200 miles at a certain speed. Had he gone 10mph faster, the trip would have taken 1 hour less. Find the speed of his vehicle.

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Steve traveled 200 miles at a certain speed. Had he gone 10mph faster, the trip would have taken 1 hour less. Find the speed of his vehicle.      Log On


   

Question 149314: Steve traveled 200 miles at a certain speed. Had he gone 10mph faster, the trip would have taken 1 hour less. Find the speed of his vehicle.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Steve traveled 200 miles at a certain speed. Had he gone 10mph faster, the trip would have taken 1 hour less. Find the speed of his vehicle.
:
Let s = his speed
:
Write a time equation: Time = dist%2Fspeed
:
200%2Fs = 200%2F%28%28s%2B10%29%29 + 1
Multiply equation by s(s+10), results:
:
200(s+10) = 200s + s(s+10)
:
200s + 2000 = 200s + s^2 + 10s
:
Subtract 200s from both sides. Arrange as a quadratic equation:
s^2 + 10s - 2000 = 0
Factor:
(s+50)(s-40) = 0
The positive solution
s = 40 mph
:
:
Check solution
200/40 = 200/50 + 1