Answer:
22 ft
Step-by-step explanation:
You want the length of one side of a square rug whose area in square feet is 396 more than its perimeter in feet.
If one side length is represented by s, then the perimeter of the square rug is ...
P = 4s
The area of that rug is the square of the side length:
A = s²
The numerical difference between these values is given as 396, so we have ...
s² -4s = 396
s² -4s +4 = 400 . . . . . . . add 4 to complete the square
(s-2)² = 400 . . . . . . . . . write as a square
s -2 = 20 . . . . . . . . . . . positive square root
s = 22 . . . . . . . . . . . . . add 2
The length of one side of the rug is 22 feet.