A=5x+20 b=9x-92 solve for x and then find the measure of a

The graph below represents the number of dolphins in a dolphin sanctuary. select all the key features of this function.

Solve: 3x+y=6 4x-2y=18 show all work !

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.