Question

Alguém responde pra mim? . X²+9x+8=0

Answer 1

$D= 9^{2} -4.1.8 \\ D= 81-32 \\ D=49 \\ \\ x'= \frac{(-b+ \sqrt{D})}{2.a} \\ OU \\ x''= \frac{(-b- \sqrt{D})}{2.a} \\ x'= \frac{(-(9)+ \sqrt{49} )}{2.1} \\ x'= \frac{-9+7}{2} = \frac{-2}{2} =-1 \\ x''=(-9- \sqrt{49} )/2 \\ x''=(-9-7)/2 \\ x''=-16/2 \\ x''=-8$

Desculpe, foi a pressa..

Answer 2

$x^2+9x+8=0\\ D=9^2-4*1*8\\ D=81-32\\ D=49\\\\ x'= \dfrac{-9+ \sqrt{49} }{2*1}\\\\ x'= \dfrac{-9+7}{2}\\\\ x'= \dfrac{-2}{2}\\\\ x'= -1\\\\\\ x''= \dfrac{-9- \sqrt{49} }{2*1}\\\\ x''= \dfrac{-9-7}{2}\\\\ x''= \dfrac{-16}{2}\\\\ x''= -8$
Espero que tenha entendido!