Answer:
3 ft
Step-by-step explanation:
You want to know the width of a uniform walkway around a 13 ft by 10 ft pool that brings the total area to 304 square feet.
If w is the width of the walkway, the total area of pool and walkway is ...
A = LW
A = (13 +2w)(10 +2w) = 130 +46w +4w² = 304
Rearranging, and dividing by 4, we have ...
w² +11.5w = 43.5
(w +5.75)² = 76.5625 . . . . . . . . complete the square
w = -5.75 ±8.75 = {-14.5, 3.0} . . . . . square root, subtract 5.75
The width of the walkway should be 3 feet.