Respostas

2014-02-26T14:33:45-03:00
(x+1) . (x-2) = -7x-10 \\  x^{2} -2x+x-2 = -7x-10 \\  x^{2} -x+7x = -10 + 2 \\  x^{2} +6x = -8 \\  x^{2} +6x + 8 =0

Determinando suas raízes:

x² + 6x + 8 = 0
Δ = (6)² - 4 (1) (8)
Δ = 36 - 32
Δ = 4

Bhaskara:

 \frac{-(6) +/- \sqrt{4} }{2(1)} \\ \\ \frac{-6 +/- 2}{2} \\ \\ \frac{-6 + 2 }{2} = \frac{-4}{2} = -2 \\ \\ \frac{-6 - 2}{2} = \frac{-8}{2} = -4

Então as raízes são: -2 e -4