SOLUTION: i must find the dimension of a rectangle a with the greatest area whose perimeter is 30 ft. is the answer 10 by 5

Question 280958: i must find the dimension of a rectangle a with the greatest area whose perimeter is 30 ft. is the answer 10 by 5
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
i must find the dimension of a rectangle a with the greatest area whose perimeter is 30 ft. is the answer 10 by 5
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Area = length*width OR LW
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Perimeter = 2(L+W)
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Your Problem:
30 = 2(L+W)
15 = L+W
W = 15-L
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Area = LW
A = L(15-L)
A = 15L-L^2
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This is a quadratic equation with a = -1 and b = 15
The Maximum area occurs when L = -b/2a = -15/(-2) = 7.5
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Answer: Length = 7.5 ft and Width = 7.5 ft.
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Cheers,
Stan H.

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