Question

resolver as equaçoes: x(x+1)+x=8

Answer 1

Olá, bom dia ☺

Resolução:

x(x+1)+x=8
x² + x + x = 8
x² + 2x - 8=0

Coeficientes:

a=1, b=2, c= -8

Valor do discriminante:

$\Delta= b^{2} -4.a.c \\ \Delta=2^2-4.1.(-8) \\ \Delta=4+32 \\ \Delta=36$

Valore de x:

$\\ x= \dfrac{-b\pm \sqrt{\Delta} }{2.a} \\ \\ x= \dfrac{-2\pm \sqrt{36} }{2.1} \\ \\ x=\dfrac{-2\pm6}{2} \\ \\ x'= \dfrac{-2+6}{2} = \dfrac{4}{2} =2 \\ \\ x''= \dfrac{-2-6}{2} = \dfrac{-8}{2} =-4$

S={2,-4}

Bons estudos :)