Amine elevator was at a depth of -120 feet. after 15 seconds, the mine elevator was at a depth of -30 feet. which expression shows how to find the speed of the mine elevator in feet per second?

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.