Respostas

2013-12-11T20:44:52-02:00
X² + 2x - 3 = 0
a = 1, b = 2, c = -3
Δ = b² - 4 a c
Δ = 2² - 4 . 1 . (-3)
Δ  = 4 + 12
Δ  = 16
x = (-b+/-√Δ)/2a
x = (-2+/-√16)/2.1
x = (-2+/-4)/2
x' = (-2+4)/2 --> x' = 2/2 --> x' = 1
x" = (-2-4)/2 --> x" = -6/2 --. x" = -3