Final answer:
The function rule for the area of a rectangle whose length is 5 ft more than its width is A = (w + 5) * w. The area of the rectangle when the width is 9 ft is 126 square feet.
Step-by-step explanation:
To find the function rule for the area of a rectangle whose length is 5 ft more than its width, you need to understand that the area of a rectangle is given by the formula A = l * w, where A represents the area, l represents the length, and w represents the width.
In this case, since the length is 5 ft more than the width, you can write the length as w + 5. So the function rule for the area would be A = (w + 5) * w.
To find the area of the rectangle when the width is 9 ft, you can substitute 9 for w in the function rule: A = (9 + 5) * 9. Simplifying this equation gives you A = 14 * 9 = 126 square feet.