Respostas

2013-07-10T17:13:58-03:00
X² + 2x - 8 = 0
a = 1, b = 2, c = -8
delta = b² - 4 . a . c
delta = 2² - 4 . 1 . (-8)
delta = 4 - 4 . (-8)
delta = 4 + 32
delta = 36

-b + ou - raiz de delta (36), sobre 2.a 
x' = -2 + 6 / 2 = 2
x" = -2 - 6 / 2 = -4

32 3 32