Question

x2+8×+7=0

me ajudem
bom dia

Answer 1

Olá, bom dia ☺

Resolução:

$\\x^{2} +8x+7=0 \\ \\ \text{Coeficientes:} \\ \\ \text{a=1,b=8,c=7} \\ \\ \text{Valor do discrimante:} \\ \\ \Delta=b^2-4.a.c \\ \Delta=8^2-4.1.7 \\ \Delta=64-28 \\ \Delta=36 \\ \\ \text{Valores de x:} \\ \\ x= \dfrac{-b\pm \sqrt{\Delta} }{2.a} \\ \\ x= \dfrac{-8\pm \sqrt{36} }{2.1} \\ \\ x= \dfrac{-8\pm6}{2} \\ \\ x'= \dfrac{-8+6}{2}= \dfrac{-2}{2} =-1 \\ \\ x''= \dfrac{-8-6}{2} =\dfrac{-14}{2} =-7$

S={-1,-7}

Bons estudos :)