Can someone look at the attachment and complete this problem for me?

How many lines can be drawn through points j and k? 0 1 2 3

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.

What is the value of x when x + 7 = 21?