Answer:
4x -10
Step-by-step explanation:
You want the side length of a square whose perimeter is (16x -40) feet.
The four sides of a square are all the same length. The perimeter is the sum of those lengths, so is 4 times the side length. Conversely, the side length is 1/4 of the perimeter.
s = P/4 = (16x -40)/4
s = 4x -10
The side length of the square table is 4x -10 feet.
