Two trains leave the station at the same time one heading east and the other west. the eastbound train travels 14 miles per hour faster than the westbound train if the two trains are 320 miles apart after 2 hours what is the rate of the eastbound train

You should look to units of measure when setting up problems. when math is done correctly, the units cancel out just as numbers and variables do.

 (miles / hr) * hr = miles

Speed = (miles / hr)

So if the Train W is traveling at x miles/hr
Then Train E is traveling (x+14) miles/hr

The combined distance they two trains travel is 320 miles

2x + 2(x+14) = 320
2x + 2x + 28 = 320
4x + 28 = 320
4x = 292
x = 292/4
x = 73 miles/hr

remember we set x as the speed for Train W
so Train E is going 73 + 14 = 87 miles/hr