Answers 5x=d that’s the answer nothing else
Answer:
standard form: y = -x^2 + 15x
1. area of a pentagon when 1 side is x is

so if perimiter is 100 then one side is 100/5 or 20
area will be

≈<span>688.2 square yards
2. area of a hexagon when 1 side is length x is

so if permiter is 100 then length of one side is 100/6 or about 16.666666666666
the area will be

≈721.7 square yards
3. area of a regular octagon with side lenghts x is

so if 8 sides then side length of each is 100/8 or 12.5
area will be

≈754.4 square yards
octagon wil have most space
you can tell because the more sides it has, the more it gets to a circle and the more area it encloses with a given perimiter
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