Write a money problem that shows money being added to and subtracted from a bank account then solve the problem

What is the range of the relation in the table below? x y –2 0 –1 2 0 4 1 2 2 0

Icould really use some with this question.

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?