SOLUTION: MATH QUESTION~ please help! The diffeence in the average speeds of two trains is 25 km/h, the faster train takes 2 hours less to travel 150km than the slower train takes to tr

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Question 761073: MATH QUESTION~
please help!
The diffeence in the average speeds of two trains is 25 km/h, the faster train takes 2 hours less to travel 150km than the slower train takes to travel 125km. Find the speeds of the two trains.
I only know that-
Distance= speed x times
Speed= Distance divided by times
Time= Distance diveded by speed
Please help!
Thank You
:D
Answer by Cromlix(4381) About Me  (Show Source):
You can put this solution on YOUR website!
150/(x - 2) - 125/x = 25
Denominator= x(x - 2)
150x - 125(x-2) = 25(x(x-2))
150x - 125x + 250 = 25x^2 - 50x
Rearrange
25x^2 - 50x - 150x + 125x + 250 = 0
25x^2 - 75x + 250 = 0
Divide by 25
x^2 - 3x + 10 = 0
(x - 5)(x + 2) = 0
So x = -2 (no answer)
x = 5
Proof
150/(5 - 2) - 125/5 = 25
150/3 - 125/5 = 25
50 - 25 = 25
50km/hr and 25 km/hr
Hope this helps.
:-)