Final answer:
The area of a rectangular deck with length x feet and width x - 4 feet is calculated using the formula A = length × width, leading to the area expression A = x² - 4x square feet.
Step-by-step explanation:
The question pertains to finding the area of a rectangular deck given its length and a relationship between its length and its width.
The length of the deck is represented by x feet, and the width is x minus 4 feet.
To find the total area, we use the formula for the area of a rectangle, which is length times width.
The area A, in square feet, can be expressed as:
A = length × width
Since the length is x and the width is x - 4:
A = x × (x - 4)
To find the area, simply multiply x by (x - 4) which will give a quadratic expression x^2 - 4x square feet.