Answer:
175 square feet
Step-by-step explanation:
the area of the whole thing is 400 ft. (20 x 20=400)
i got the 20 from the perimeter b/c 20+20+20+20=80
then subtract the area of the pool from 400 to get 175.
I believe its $6.95 but i did that in my head so i might be wrong
the horizontal tangent line mean y'=0
8 - 2x = 0
x = 4
