Linear equations

Question

Two trains are 1200miles apart and are on a non-stop trip towards Denver. Train A is traveling at 75mph and left its last stop at 3:00pm. Train B left its last stop at 1:00pm and is traveling at 60mph. What time will it be when the two trains meet in Denver? Write a system of linear equations, solve it, and then answer the question.

Answer 1

Let x = number of hours after 1 PM

Distance = (Rate)(Time)

Distance of train A = 75(x - 2)

Distance of train B = 60x

When the trains meet at Denver, the total distances travelled by the trains is 1200 miles.

So, 75(x - 2) + 60x = 1200

135x - 150 = 1200

135x = 1350

x = 10 (The trains meet 10 hours after 1 PM. That is, they meet at 11 PM)