SOLUTION: a man made a trip of 432 miles by car. if the average speed had been 6 miles per hour faster, the trip would have taken one hour less. how long did the trip take and what was his a

Question 1031723: a man made a trip of 432 miles by car. if the average speed had been 6 miles per hour faster, the trip would have taken one hour less. how long did the trip take and what was his average speed?
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
speed x
speed x + 6

Distance = same 432 km 1
original time � time with increased speed = 1 hour
t=d/t
432 / x - 432 / ( x + 6 ) = 1
LCD= x ( x + 6 )
multiply by LCD
432 ( x + 6 ) - 432 x = 1 x ( x + 6 )
432 x + 2592 - 432 x = 1 X^2 + 6 x
2592 = x^2 + 6 x
x^2 + 6 x - -2592 = 0
x^2 +6x +9 = 2592+9
(x+3)^2 =2601
(x+3) = +/-
x+3 = +/- 51
x= 51-3 = 48 km/h

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