Two trains are traveling towards each other at a constant speed. the trains are currently 714 miles from each other. the speeds of the trains differ by 8 miles per hour. the trains will meet in 7 hours. what is the speed of the faster train?

55mph.

you can solve it using the equation distance=speed x time

your total distance is 714, and you have 2 trains, one traveling some speed, x, and one traveling x+8, both traveling for 7 hours. 
your equation would look like this

and you can then solve for x, which would be 47. this is the speed of the slower train, but 47+8=55 with give you the speed of the faster train.