Question

equacao do 2 grau X2-11x +18=0

Answer 1

$x^2 - 11x + 18 = 0 \\ \\ a = 1 \\ b = -11 \\ c = 18 \\ \\ x = \frac{-b\pm \sqrt{b^2-4.a.c} }{2.a} \\ \\ x = \frac{-(-11)\pm \sqrt{(-11)^2-4.1.18} }{2.1} \\ \\ x = \frac{11\pm \sqrt{121-72} }{2} \\ \\ x =\frac{11\pm \sqrt{49} }{2} \\ \\ x = \frac{11\pm7}{2} \\ \\ \\ x' = \frac{11+7}{2} \rightarrow x' = \frac{18}{2} \rightarrow x' = 9 \\ \\ x'' = \frac{11-7}{2} \rightarrow x'' = \frac{4}{2} \rightarrow x'' = 2$

Raízes da equação:

$x' = 9 \\ x'' = 2$

Answer 2

Explicação passo-a-passo:

$\sf x^2-11x+18=0$

$\sf \Delta=(-11)^2-4\cdot1\cdot18$

$\sf \Delta=121-72$

$\sf \Delta=49$

$\sf x=\dfrac{-(-11)\pm\sqrt{49}}{2\cdot1}=\dfrac{11\pm7}{2}$

$\sf x'=\dfrac{11+7}{2}~\Rightarrow~x'=\dfrac{18}{2}~\Rightarrow~\red{x'=9}$

$\sf x"=\dfrac{11-7}{2}~\Rightarrow~x"=\dfrac{4}{2}~\Rightarrow~\red{x"=2}$