SOLUTION: A man drives 500 km. to a business convention on the return trip he increases his speed by 25 km/hr. and saves i hr. driving time. How fast did he go in each direction?

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Question 890056: A man drives 500 km. to a business convention on the return trip he increases his speed by 25 km/hr. and saves i hr. driving time.
How fast did he go in each direction?


Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
r*t=d
.
r*t=500
r=500/t
((500/t)+25)*(t-1)=500
500t+25t^2-500-25t=500t Multiply each side by t.
25t^2-25t-500=0
t^2-t-20=0
(t-5)(t+4)=0
t=5 hrs
r=100 k/h going
125 k/h returning
.
Ed