Caleb and Landon work at a dry cleaners ironing shirts. Caleb can iron 30 shirts per hour, and Landon can iron 15 shirts per hour. Caleb worked 2 more hours than Landon and they ironed 330 shirts between them. Write a system of equations that could be used to determine the number of hours Caleb worked and the number of hours Landon worked. Define the variables that you use to write the system.