A can of soda costs $1.20 in the United States and 30 pesos in Mexico. Assume purchasing-power parity holds. The peso–dollar exchange rate is pesos per dollar. Suppose a monetary expansion causes all prices in Mexico to double, so that the price of soda in Mexico rises to 60 pesos. The peso–dollar exchange rate is now pesos per dollar.

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.