Question 167792
(L + 2) (L – 4) = 20 cm2, find L
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L^2-2L-8 = 20
L^2-2L-28 = 0
L = [2 +- sqrt(4-4*1*-28)]/2

L = [2 +- sqrt(116)]/2

L = [2 +- 2sqrt(29)]/2

L = 1+sqrt(29) or x = 1-sqrt(29)
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Cheers,
Stan H.