The Danville Epress travels 280mi at a certain speed.If the speed had been increased by 5mph the trip could have been made in 1 hour less time.Find the actual speed.
let actual speed be x mph
Case 1:
Time to go 280 miles at x mph takes 280/x hours
Case 2:
Time to go 280 miles at (x+5) mph takes 280/(x+5) hours
280/x - 280/(x+5) = 1
280(x+5) - 280x = x(x+5)
280x + 1400 - 280x = x^2 + 5x
x^2 + 5x - 1400 = 0
(x-35)(x+40) = 0
x =35 or x = -40 , but x > 0
x = 35 mph