Question

Resolva as equações de 2° grau em IR ×2+2×-8=0

Answer 1

Explicação passo-a-passo:

$\sf x^2+2x-8=0$

$\sf \Delta=2^2-4\cdot1\cdot(-8)$

$\sf \Delta=4+32$

$\sf \Delta=36$

$\sf x=\dfrac{-2\pm\sqrt{36}}{2\cdot1}=\dfrac{-2\pm6}{2}$

$\sf x'=\dfrac{-2+6}{2}~\Rightarrow~x'=\dfrac{4}{2}~\Rightarrow~\red{x'=2}$

$\sf x"=\dfrac{-2-6}{2}~\Rightarrow~x"=\dfrac{-8}{2}~\Rightarrow~\red{x"=-4}$