## Elementary Algebra

Let s represent the selling price. The basic relationship is: selling price equals cost plus profit. Selling price = Cost + Profit Selling price = s Cost = 32 Profit = 20% $\times$ s = 0.2s We substitute these values into the equation to obtain: s = 32 + 0.2s 0.8s = 32 Divide both sides by 0.8 s = 40 He should charge 40 dollars for one pair of shoes.