Melanie is tiling her shower with blue and white square tiles. She needs enough tiles to cover 72 square feet. Each tile is the same size. To get the look that she wants, Melanie will use x blue tiles and y white tiles per square foot. Complete the steps below to determine the number of tiles Melanie needs in terms of x and y. Part A Write an expression in terms of x and y that represents the total number of tiles needed per square foot.