In a park, a picnic area is surrounded by grass in the shape of a rectangle, as shown in the diagram below. If the area of the shaded region that represents the grass is 48 square yards, what is the length and width of the picnic area? How could we write an expression to represent the area of the larger rectangle?
Area =
How could we write an expression to represent the area of the smaller rectangle?

How could we write an expression that only represents the area of the shaded region?

If the area of the shaded region is 48 square feet, what is x?