At a portrait studio, three 8-inch-by-10-inch pictures and two 5-inch-by-7-inch pictures cost a total of $52. Two 8-inch-by-10-inch pictures and two 5-inch-by-7-inch pictures cost a total of $40. This situation can be represented by the system of equations, where x is the cost in dollars of each 8-inch-by-10-inch picture and y is the cost in dollars of each 5-inch-by-7-inch picture. What is the cost of one 5-inch-by-7-inch picture?