Solving a distance, rate, time problem using a linear equation

Question

Two trains leave the station at the same time, one heading east and the other west. The westbound train travels 20 miles per hour slower than the eastbound train. If the two trains are 750 miles apart after 5 hours, what is the rate of the westbound train? Do not do any rounding.

Answer 1

W = E-20

distance = rate of speed times time traveled

d = rt

750 = 5E + 5(E-20) =5E + 5E -100 = 10E -100

10E = 750+100 = 850

E = 850/10 = 85 mph for the east bound train

W= 85-20 = 65 mph for the west bound train

5(85) + 5(65) = 425 + 325 = 750