At Sirens cafe, a small latte sells for $2.50, a medium latte sells for $3.00 and a large latte selss for 3.25. During the morning rush, Kim sold 45 lattes for a total of $139. The number of small and medium lattes combined is six fewer than twice the number of large lattes. How many of each size were sold? Set up a sysstem of three equations for this problem. (do not solve)