Aston university creates a 10 digit student number as the university enrolls each student. the first two characters must be a digit 1 through 9. the next seven characters can be anything and the last digit just can’t be the same as the ninth character (i. e. the previous digit). how many student numbers are possible?

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.