Answer:
d= 17.03
Step-by-step explanation:
21x^2-2x+1
The area of shaded region= The area of the floor - area of the identical islands
The area of shaded region=(5x+1)^2-2*(2x)(x+3)=25x^2+1+10x-4x^2-12x=21x^2-2x+1
44.5 is the best