Answer:
1)

2A)

2B)

Explanation:
1)
First, let's write the expressions for the area of the entire shaded region and the white area.
The formula for the area of a rectangle is given by:

For the entire shaded rectangle, the length is (4x) and the width is (x+2). So, the area is:

For the white rectangle, the length is (3x+5) and the width is (x). So, the area is:

The shaded area is the entire shaded rectangle minus the area of the white rectangle. Therefore, our expression would be:

2)
Part A)
So, we are given that the length of the rectangle is 3 inches greater than the width.
The area of a rectangle is given by:

So, let w be width and let l be the length.
Since the length is 3 inches greater than the width, this means that the l is (w+3).
Thus, substitute. Our expression will therefore be:

Since we want a polynomial, let's expand:

Part B)
To find the area when the width is 4, substitute 4 for w:

Square and multiply:

Add:

So the area is 28 square inches.