Respostas

2013-12-11T15:31:21-02:00
X² - x - 2 = 0
Delta = (-1)² - 4 . 1 . (-2)
Delta = 1 + 8
Delta = 9

x = (1 ± raiz de 9) / 2

x'= (1 + 3) / 2   ---> x' = 4/2 
   ---> x' = 2
x"= (1 - 3) / 2   ---> x" = -2/2    ---> x" = -1
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