SOLUTION: I have another problem that I need help with A car travels 360 miles at a certain speed. If the speed had been 5mph faster the trip would have been made in 1 hr less time. Find

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Question 459347: I have another problem that I need help with
A car travels 360 miles at a certain speed. If the speed had been 5mph faster the trip would have been made in 1 hr less time. Find the speed. Thank you.
Found 2 solutions by sudhanshu_kmr, htmentor:
Answer by sudhanshu_kmr(1152) (Show Source):
You can put this solution on YOUR website!

speed = x miles/h
360/x - 1 = 360/(x+5)
=> 360/x - 360/x+5 = 1
=> 360 * 5 = x(x+5)
=> 1800 = x^2 + 5x
=> x^2 + 5x- 1800 = 0
=> x^2 + 45x -40x - 1800 = 0
=> x(x+45) -40(x +45) = 0
=> (x+45)(x-40) = 0

so, x = 40, ( x = -45 not possible)
speed = 40 miles/h

Answer by htmentor(1343) (Show Source):
You can put this solution on YOUR website!
A car travels 360 miles at a certain speed. If the speed had been 5mph faster the trip would have been made in 1 hr less time. Find the speed.
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Let s = the speed of the car
Let t = the original time
Then the time to travel the 360 miles is:
t = 360/s
If the speed were 5 mph faster, the time [in hrs] would have been:
t - 1 = 360/(s+5)
Using the value for t in the 1st equation gives:
360/s - 1 = 360/(s+5)
Solve for s:
(360 - s)/s = 360/(s+5)
360s + 360*5 - s^2 - 5s = 360s
s^2 + 5s - 1800 = 0

Take the positive solution.
s = (-5 + 85)/2 = 40
So the speed of the car is 40 mph