Question 253929: Address book. The perimeter of the cover of an address book is 14 inches, and the diagonal measures 5 inches. What are the length and width of the cover?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Address book. The perimeter of the cover of an address book is 14 inches, and the diagonal measures 5 inches. What are the length and width of the cover?
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Perimeter = 2(L + W) = 14"
L+W = 7"
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Pythagorean
L^2 + W^2 = 5^2
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L = 7-W
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Substitute for "L":
(7-W)+W^2 = 25
49 - 14W + 2W^2 = 25
2W^2 - 14W + 24 = 0
W^2 - 7W + 12 = 0
(W-3)(W-4) = 0
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If W = 3, L = 7-W = 4
If W = 4, L = 7-W = 3
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Cheers,
Stan H.
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