A school is organizing a cookout where hotdogs will be served. The hotdogs come in small packs and large packs. Each small pack has 10 hotdogs and each large pack has 18 hotdogs. The school bought 6 packs of hotdogs that have a total of 76 hotdogs. Write a system of equations that could be used to determine the number of small packs purchased and the number of large packs purchased. Define the variables that you use to write the system.