A boat traveled 189 miles downstream and back. The trip downstream took 9 hours. The trip upstream took 63 hours. Find the speed of the boat in still water and the speed of the current. (What are the variables, system of equations, solutions, and answer to question?)

Three students, javier, sam, and corrine, participated in a fundraiser where people donated a certain amount of money per lap that the student ran. each student also had some initial donations that were collected before the run. the equations that represent each student's total donation, y, based on the number of laps ran, x, is shown below. match each equation with the correct rate of change for that student.