
Patrick B. answered 03/09/20
Math and computer tutor/teacher
(1)
then the side measures of the square become 23 + 2d
the area is then (2d + 23)(2d + 23) = 4d^2 + 92d + 529
(2) for d=12, the total area is (2*12+23)^2 = (24+23)^2 = 47^2 = 2209..
OR you can do 4*12^2 + 92*12 + 529 = 4*144+ 92*12 + 529 = 2209
(3) the volume of the pool is 23*23*5 = 2645 cubic feet
2645 / 0.134 = 19738.805+..... gallons are needed.
$1.50 per 1000 gallons means
19.738805... * 1.50 = $29.61 + tax