Part 1:
The area of a square is:

The length of each side will be given by:

Substituting we have that the area is:

Part 2:
Substituting the area we have:
y = (6 + 2x) ^ 2

Part 3:
We solve the equation for x:




Part 4:
The width of the deck around the hot tub is:
3.5 feet