The rectangle below has an area of 81 - x^2 square meters and a width of 9 - x meters

The width would be 9 + x

Step-by-step explanation:

In order to find this, we must first factor the area. This will give us two things that are being multiplied together.

81 - x^2 = (9 - x) (9 + x)

Since the area is the length times the width and the width is x - 9, we know the length must be x + 9