Tara plans to put wallpaper on the walls of her room. she will not put the wallpaper across the doorway, which is 3 feet wide and 7 feet tall. find the expression which represents the number of square feet of wallpaper she will need if the height of her room is x feet, with a length and width that are each 3 times the height of the room. assume that the walls are four rectangles. tara will need square feet of wallpaper for her bedroom.