20−6+4k=2−2k plz solve

The diameter of a circular chip is doubled to use in a new board game. the area of the new chip will be

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.

Having a hard time understanding this question (see attachment).