Respostas

A melhor resposta!
2014-08-19T19:02:39-03:00
(x - 1) · (x + 3) = 5

x² + 3x - x - 3 = 5

x² + 2x - 8 =0
/a = 1; b = 2; c = -8/

Δ = b² - 4ac
Δ = 4 - 4· 1 · (-8)
Δ = 4 + 32
Δ = 36

x`,, = \dfrac{-b +- sqrt{Δ}}{2a}~=

x`,, = \dfrac{-4 +- sqrt{36}}{2 \cdot1}~=

x`,, = \dfrac{-4 +- 6}{2} =

x` = \dfrac{-4 + 6}{2} =            x,, = \dfrac{-4 - 6}{2} =

x` = \dfrac{2}{2} =            x,, = \dfrac{-10}{2} =
 
x` = 1            x,, = -5
1 5 1