• Matéria: Matemática
  • Autor: AlexandreNeuburger
  • Perguntado 9 anos atrás

ajuda, como resolver isso?

Anexos:

Respostas

respondido por: rebecaamesquitaa
1
........................
Anexos:
respondido por: Anônimo
0
Boa noite Alexandre!

Solução!

 \sqrt{x+6}=x\\\\\\
( \sqrt{x+6} )^{2}=(x)^{2}\\\\\\
x+6= x^{2} \\\\\
 x^{2} -x-6=0




x=  \dfrac{1\pm \sqrt{(-1) ^{2}-4.1.-6 } }{2.1} \\\\\\
x=  \dfrac{1\pm \sqrt{1+24 } }{2} \\\\\\
x=  \dfrac{1\pm \sqrt{25 } }{2} \\\\\\

x=  \dfrac{1\pm5}{2} \\\\\\\\\\
Raizes\\\\\\\
 x_{1}= \frac{1+5}{2}= \dfrac{6}{2}=3  \\\\\\\
 x_{2}= \frac{1-5}{2}= \dfrac{-4}{2}=-2~~nao~~serve\\\\\\\\\\\
\boxed{Resposta: x_{1}=3~~Alternativa~~B}

Boa noite!
Bons estudos!

Perguntas similares