Ashwin helps paint a square mural in his classroom. Then he helps paint a mural in the hallway whose length is 7 feet long and whose width is 3 feet shorter. Let x represent the side length of the mural in Ashwin's classroom. Write an expression that represents the two binomials you would multiply to find the area of the hallway mural. Use that expression to find the area of the hallway mural if each side of the classroom mural is 8 feet long.