A rectangular piece of cardboard measuring 12 in by 18 in is to be made into a box by cutting equal size squares from each corner and folding up the sides. Let x represent the length of a side of each such square in inches. Answer the following questions.
A rectangle surrounded by a border that has a width labeled x and makes a larger rectangle. The horizontal side of the larger rectangle is 12 inches and the vertical side of the small rectangle is 18 inches.