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

pfv respondao essa equação do segundo grau com calculo

Anexos:

Respostas

respondido por: Anônimo
1
Boa noite Luiz!

Solução!

 \dfrac{x-2}{3x}+ \dfrac{2x-1}{2} = \dfrac{5x+2}{6}\\\\\\

MMC=36x\\\\\\
12(x-2)+18x(2x-1)=6x(5x+2)\\\\\\
12x-24+36 x^{2} -18x=30 x^{2} +12x\\\\\\\
36 x^{2} -30 x^{2} +12x-12x-18x-24=0\\\\\\\
6 x^{2} -18x-24=0\\\\\\\
Vamos~~dividir~~a~~equac\~ao~~por~~6!

6 x^{2} -18x-24=0:6\\\\\\\
 x^{2} -3x-4=0\\\\\
Vamos ~~usar~~ a ~~formula ~~de~~ Bhaskara!


a=1~~~~~b=-3~~~~~~c=-4\\\\\\\
x= \dfrac{-b\pm \sqrt{b^{2}-4.a.c } }{2.a}\\\\\\

x= \dfrac{-(-3)\pm \sqrt{(-3)^{2}-4.1.(-4) } }{2.1}\\\\\\
x= \dfrac{3\pm \sqrt{9+16 } }{2}\\\\\\
x= \dfrac{3\pm \sqrt{25 } }{2}\\\\\\
x= \dfrac{3\pm 5}{2}\\\\\\\\
 x_{1}= \dfrac{3+5}{2}= \dfrac{8}{2}=4\\\\\\
x_{2}= \dfrac{3-5}{2}= \dfrac{-2}{2}=-1\\\\\\\\\
\boxed{Resposta:S=\{-1,4\}~~\boxed{Alternativa~~B}}

Boa noite!
Bons estudos!


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