Question

-x²-4x+5=0
pvv me ajudem eu preciso muito:o​
(com cálculo)

Answer 1

Resposta:

$\textsf{Leia abaixo}$

Explicação passo a passo:

$\mathsf{-x^2 - 4x + 5 = 0}$

$\mathsf{x^2 + 4x - 5 = 0}$

$\mathsf{\Delta = b^2 - 4.a.c}$

$\mathsf{\Delta = 4^2 - 4.1.(-5)}$

$\mathsf{\Delta = 16 + 20}$

$\mathsf{\Delta = 36}$

$\mathsf{x = \dfrac{-b \pm \sqrt{\Delta}}{2a} = \dfrac{-4 \pm \sqrt{36}}{2} \rightarrow \begin{cases}\mathsf{x' = \dfrac{-4 + 6}{2} = \dfrac{2}{2} = 1}\\\\\mathsf{x'' = \dfrac{-4 - 6}{2} = -\dfrac{10}{2} = -5}\end{cases}}$

$\boxed{\boxed{\mathsf{S = \{1;-5\}}}}$