Louis plans to buy a new washing machine. the washing machine costs $560 and has an estimated annual operating cost of $48. which rational function models the average annual cost in dollars of owning the washing machine for x years?

(560+48x)/x. After owning the washing machine for x years, with operating cost of $48 each year, the total amount of operating cost is 48x. We should also add the one-time cost of buying the washing machine, which is $560. The total cost is 560+48x. Since x years have past, the average annual cost is (560+48x)/x, or 48+560/x dollars.