Last year, miguel opened an investment account with $7800. at the end of the year, the amount in the account had increased by 7.5%. how much increase is this in dollars? how much money was in his account at the end of last year?

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.