You are buying a t-shirts for the math club members. The t-shirt company will charge you according to the amount of shirts you buy, where c(x) is the total cost and x, is the number of shirts. If you buy 10 or less shirts it cost 12 dollars per shirt, if between 11 and 50 it will cost 10 dollars per shirt, then if you buy more then 50 it will cost 8 dollars per shirt. What is your equation if you buy 9 shirts. *