Mr. rivera bought some erasers to give his students. on monday , mr. rivera gave out 22 erasers. on Tuesday, he gave out 39 earsers. on Wednesday , he bought 76 earsers. now he has 193 . how many earsers did mr. rivera start with ?

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.