CAN SOmEONE PLZ HELP ME ASAP

Iwant to know what 3g+5h+4g-2h is my teacher is too selfish to tell us

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.

4+(2+x) can you me solve this problem