Sally wants to buy new fish for her fish tank. She buys goldfish and swordfish. Goldfish cost $.50 and swordfish cost $2.50. She buys 24 fish and spends a total of $40.00. How many of each type of fish does she buy? Create a system of equations to represent this problem. Then, solve the system using any method. (If anyone could also explain it that would be great :D)