
Leslie M. answered 05/28/19
Certified math teacher and experienced tutor
If the two trains are leaving from the same station and travelling in opposite directions, then their distances will get added together. You want to find the time t (hours) where the two distances add up to 495 miles.
Use the formula distance = rate x time to find the distance that each train travels in t hours. (Keep the variable for t, because it is the same for both trains, and it is the value the question is looking for.)
First train: d1 = r1t = 45t
Second train: d2 = r2t = 54t
Combined distance = d1+ d2 = 45t + 54t = 99t
Since you want the combined distance to be 495 miles, solve the algebraic equation to find the time t when that happens.
Hope this helps!