Question

calculo de 5x²-12x-7=0

Answer 1

Resposta:

$\textsf{Leia abaixo}$

Explicação passo a passo:

$\mathsf{5x^2 - 12x - 7 = 0}$

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

$\mathsf{\Delta = (-12)^2 - 4.5.(-7)}$

$\mathsf{\Delta = 144 + 140}$

$\mathsf{\Delta = 284}$

$\mathsf{x = \dfrac{-b \pm \sqrt{\Delta}}{2a} = \dfrac{12 \pm \sqrt{284}}{10} \rightarrow \begin{cases}\mathsf{x' = \dfrac{12 + 2\sqrt{71}}{10} = \dfrac{6 + \sqrt{71}}{5}}\\\\\mathsf{x'' = \dfrac{12 - 2\sqrt{71}}{10} = \dfrac{6 - \sqrt{71}}{5}}\end{cases}}$

$\mathsf{S = \left\{\dfrac{6 + \sqrt{71}}{5};\dfrac{6 - \sqrt{71}}{5}\right\}}$