SOLUTION: Imogene's car traveled 360 mi averaging a certain speed. If the car had gone 5 mph faster, the trip would have taken 1 hour less. Find the average speed.

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Question 1066484: Imogene's car traveled 360 mi averaging a certain speed. If the car had gone 5 mph faster, the trip would have taken 1 hour less. Find the average speed.
Answer by ikleyn(52792) About Me  (Show Source):
You can put this solution on YOUR website!
.
360%2Fu+-+360%2F%28u%2B5%29 = 1,

360*(u+5) - 360u = u*(u+5),

360u + 1800 - 360u = u^2 + 5u,

u^2 + 5u - 1800 = 0.

(u+45)*(u-40) = 0.

Answer. 40 mph.