At a particular restaurant, each onion ring has 40 calories and each mini hotdog has 80 calories. A combination meal with onion rings and mini hotdogs has a total of 19 onion rings and mini hotdogs altogether and contains 1080 calories. Write a system of equations that could be used to determine the number of onion rings in the combination meal and the number of mini hotdogs in the combination meal. Define the variables that you use to write the system.