Question 69992
Steve traveled 600 miles at a certain speed. Had he gone 20mph faster, the trip would have taken 1 hour less. Find the speed of his vehicle.
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1st trip DATA:
distance = 600 miles ; rate= x mph ; time= d/r = 600/x hrs.
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Imaginary trip DATA:
distance = 600 miles ; rate = "x+20" mph ; time = d/r = 600/(x+20)
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EQUATION:
1st trip time = imaginary trip time + 1 hr.
600/x = 600/(x+20) + 1
Multiply thru by x(x+20) 
600(x+20)= 600x +x(x+20)
12000 = x^2+20x
x^2+20x-12000=0
(x+120)(x-100)=0
x=100 mph (speed of his vehicle)
Cheers,
Stan H.