Question

determine o valor de ×: 4ײ-12=-8×

Answer 1

4x² - 12 = - 8x

4x² - 12 + 8x = 0

4x² + 8x - 12 = 0 ( : 4 )

x² + 2x - 3 = 0

$x = \frac{ - b + - \sqrt{ {b}^{2} - 4ac} }{2a}$

$x = \frac{ - ( + 2) + - \sqrt{ {2}^{2} - 4.1. - 3} }{2.1}$

$x = \frac{ - 2 + - \sqrt{4 + 12} }{2}$

$x = \frac{ - 2 + - \sqrt{16} }{2}$

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

$x1 = \frac{ - 2 - 4}{2}$

$x1 = \frac{ - 6}{2}$

x' = - 3

$x2 = \frac{ - 2 + 4}{2}$

$x2 = \frac{2}{2}$

x'' = 1

S = { - 3 , 1 }