Question

Encontre os valores de X 1 e X2 para X²+3x+2=0 :

a) (2,1)

b) (-3,-1)

c) (-2,-1)

d)(-1)​

Answer 1

$x^{2} +3x+2=0\\ \\ a=1~~,~~b=3~~,~~c=2\\ \\ \\\\ \dfrac{-b\pm\sqrt{b^{2}-4\cdot a\cdot c} }{2\cdot a} ~~\to~~ \dfrac{-3\pm\sqrt{3^{2}-4\cdot 1\cdot 2} }{2\cdot 1} ~~\to~~\dfrac{-3\pm\sqrt{1} }{2} \\ \\ \\ \\ \\ x_{1} =\dfrac{-3+1}{2} =-\dfrac{2}{2} ~~\to~~ \boxed{x_{1}=-1 } \\ \\ \\ x_{2} =\dfrac{-3-1}{2} =-\dfrac{4}{2} ~~\to~~ \boxed{x_{2}=-2 }$

Resposta:

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Alternativa c)

:)