Question

-x2 + x + 12=0 mas a equaçao no segundo grau

Answer 1

OLÁ

VAMOS A SUA PERGUNTA:⇒⇒

$\sf \: -x ^ { 2 } +x+12=0$

$\sf \: -x^{2}+x+12-12=-12$

$\sf-x^{2}+x=-12$

$\sf\dfrac{-x^{2}+x}{-1}=\dfrac{-12}{-1}$

$\sf \: x^{2}+\dfrac{1}{-1}x=\dfrac{-12}{-1}$

$\sf \: x^{2}-x=\dfrac{-12}{-1}$

$\sf \: x^{2}-x=12$

$\sf \: \: x^{2}-x+\left(-\dfrac{1}{2}\right)^{2}=12+\left(-\dfrac{1}{2}\right)^{2}$

$\sf \: x^{2}-x+\dfrac{1}{4}=12+\dfrac{1}{4}$

$\sf \: x^{2}-x+\dfrac{1}{4}=\dfrac{49}{4}$

$\sf \: \left(x-\dfrac{1}{2}\right)^{2}=\dfrac{49}{4}$

$\sf\sqrt{\left(x-\dfrac{1}{2}\right)^{2}}=\sqrt{\dfrac{49}{4}}$

$\sf \: x-\dfrac{1}{2}=\dfrac{7}{2} \\ \sf x-\dfrac{1}{2}=-\dfrac{7}{2}$

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