Troy must keep track of the amount of refrigerant he uses from a​ 50-pound cylinder to ensure that accurate records are kept. He used 13 pounds on a system for Ms. Jones and 9 pounds on a system for a commercial client. How many pounds should he have left in the​ cylinder?

Frank has a devised a formula for his catering business that calculates the number of meatballs he needs to prepare. the formula is m=4a+2c, where c=number of children; m=number of meatballs; a=number of adults. how many meatballs are required for a party of 10 adults and 5 children?