A car travel at constant speed from Q to R, a distance of 300 km apart. If the drive increases the speed by 5 km/h, the journey will take 2 hours less. Find the original speed of the car.

Answer 1

Original speed --- x km/h
time at original speed = 300/x hrs

new speed ---- x+5
time at new speed = 300/(x+5)

300/x - 300/(x+5) = 2

solve for x, after multiplying all terms by x(x+5) to get your quadratic