Let x = the width of the border
2x+23) by (2x + 33) are the overall dimensions of the pool and the border. Use the area to find x!
Overall area - pool area = 660 sq/ft (aggregate area)
(2x+23)*(2x+33) - (23*33) = 660
Solve.
4x^2+112x = 660
4x^2+112x−660=0 → subtract 660 on both sides
4(x−5)(x+33)=0 → factor
x−5=0 or x+33=0 → set both factors equal to 0
x = 5 or x = -33
In this case, we would use the positive solution, so the strip can be 5 ft. wide!
I hope this helps :)
