Anna maria bought 3 more boxes of erasers. there are 10 pencils in each box of pencils and 20 erasers in each box of erasers. if the number number of pencils that anna marie bought equals the number of erasers that she bought. how many pencils did anna maria buy?

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.