How do I find the missing side of this special right triangle?

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.

Mis the midpoint of rq if rm equals 2x + 5 and mq equals 4x - 9 what is the length of rq

Tom drove 206 miles in 3.9 hours. estimate his average speed.