Question

${x }^{2} - x - 6 = 0$
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Answer 1

Resposta:

$\textsf{Leia abaixo}$

Explicação passo-a-passo:

$\mathsf{x^2 - 5x + 2 = 0}\rightarrow\begin{cases}\mathsf{a = 1}\\\mathsf{b = -1}\\\mathsf{c = -6}\end{cases}$

$\mathsf{\Delta = b^2 - 4.a.c}$

$\mathsf{\Delta = (-1)^2 - 4.1.(-6)}$

$\mathsf{\Delta = 1 - 24}$

$\mathsf{\Delta = 25}$

$\mathsf{x = \dfrac{-b \pm \sqrt{\Delta}}{2a} = \dfrac{1 \pm \sqrt{25}}{2} \rightarrow \begin{cases}\mathsf{x' = \dfrac{1 + 5}{2} = \dfrac{6}{2} = 3}\\\\\mathsf{x'' = \dfrac{1 - 5}{2} = \dfrac{-4}{2} = -2}\end{cases}}$

$\boxed{\boxed{\mathsf{S = \{3\:;-2\}}}}$