Question

x² - 2 x - 5 = 0 resolva​

Answer 1

${x}^{2} - 2x - 5 = 0$

$x = \frac{ - ( - 2) + - \sqrt{ {( - 2)}^{2} - 4 \times 1 \times ( - 5) } }{2 \times 1}$

$x = \frac{2 + - \sqrt{4 + 20} }{2}$

$x = \frac{2 + - 2 \sqrt{6} }{2}$

$x = \frac{2 + 2 \sqrt{6} }{2} = 1 + \sqrt{6} \\ x = \frac{2 - 2 \sqrt{6} }{2} = 1 - \sqrt{6}$