A hearing aid clinic is trying to determine how many batteries to purchase: The more batteries the clinic purchases the cheaper the batteries are_ However; storing the batteries costs money (in the form of renting space): The cost of ordering x boxes of batteries is given by the function 21x 21 In(x). The cost of storing x boxes of batteries is given by the equation S(x) 0.09(x 50)²

Write an equation that models the total cost of purchasing and storing x boxes of batteries
Total cost:_____ dollars