Question

x^{2} -13x + 21= 3 , solução por favor e desenvolvimento

Answer 1

Resposta:

OLÁ

VAMOS A SUA PERGUNTA:⇒⇒

$\sf x^{2} -13x + 21= 3$

$\sf x^2-13x+21-3=3-3$

$\sf x^2-13x+21-3=0$

$\sf x^2-13x+18=0$

$\sf x=\dfrac{-(-13)\pm\sqrt{(-13)^2-4\times18} }{2}$

$\sf x=\dfrac{-(-13)\pm\sqrt{169-4\times18} }{2}$

$\sf x=\dfrac{-(-13)\pm\sqrt{169-72} }{2}$

$\sf x=\dfrac{-(-13)\pm\sqrt{97} }{2}$

$\sf x=\dfrac{13\pm\sqrt{97} }{2}$

$\sf \red{x=\dfrac{\sqrt{97}+13 }{2}\approx11.424428901 }$

$\sf \green{x=\dfrac{13-\sqrt{97} }2} \approx1.575571099}$

$\boxed{\bold{\displaystyle{\clubsuit\ \spadesuit\ \maltese\ \sf \red{x=\dfrac{\sqrt{97}+13 }{2}\approx11.424428901 } }}}\ \checkmark \\\boxed{\bold{\displaystyle{\clubsuit\ \spadesuit\ \maltese\ \sf \green{x=\dfrac{13-\sqrt{97} }2} \approx1.575571099}}}}\ \checkmark$←←↑↑⇆ ⇄⇵⇵ RESPOSTA.

Explicação passo-a-passo:

ESPERO TER AJUDADO

Answer 2

Oie, Td Bom?!

$x {}^{2} - 13x + 21 = 3$

$x {}^{2} - 13x + 21 - 3 = 0$

$x {}^{2} - 13x + 18 = 0$

• Coeficientes:

$a = 1 \: ,\: b = - 13 \: , \: c = 18$

• Fórmula resolutiva:

$x = \frac{ - b± \sqrt{b {}^{2} - 4ac} }{2a}$

$x = \frac{ - ( - 13)± \sqrt{( - 13) {}^{2} - 4 \: . \: 1 \: . \: 18} }{2 \: . \: 1}$

$x = \frac{13± \sqrt{169 - 72} }{2}$

$x = \frac{13± \sqrt{97} }{2}$

$S = \left \{ \frac{13 - \sqrt{97} }{2} \: , \: \frac{13 + \sqrt{97} }{2} \right \}$

Att. Makaveli1996