A shoe store orders shoes from the manufacturer and sells them at a mall. Storing shoes at the store costs $6 per shoe pair for a year. When reordering shoes from the manufacturer, there is a fixed cost of $30 per order as well as $6 per shoe pair. The retail store sells 2500 shoe pairs each year. Find a function that models the total inventory costs as a function of x x the number of shoe pairs in each order from the manufacturer.