Question 413587
designing a pool where the area 16 and the perimeter is 20.
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assuming it's a rectangular pool...
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Let W = width
and L = length
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from knowledge of perimeter:
2(W+L) = 20 
W+L = 10 (equation 1)
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from knowledge of area:
WL = 16 (equation 2)
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Solving equation 1 for L we get:
L = 10-W
Substitute into equation 2:
W(10-W) = 16
W^2+10W = 16
W^2+10W-16 = 0
Applying the quadratic formula we get:
W = {1.4, -11.4}
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Find L by substitutiting above into equation 1:
1.4+L = 10
L = 8.6
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Dimensions are: 1.4 by 8.6 
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Details of quadratic follows
*[invoke quadratic "W", 1, 10, -16 ]