Question

Resolva a equação:
$(-2x - 1) . (x - 2) = 3x + 5x^{2}$

Answer 1

$(-2x - 1) . (x - 2) = 3x + 5x^{2} \to \\\\\\ -2 x^{2} +4x-x+2= 3x + 5x^{2} \to \\\\ -2 x^{2} +4x-x+2-3x - 5x^{2}=0 \to \\\\ -2 x^{2} -5 x^{2} +4x-x-3x +2=0\to \\ \\-7 x^{2} +2=0\to \\\\ -7 x^{2} =-2\to \\\\ x^{2} = \frac{-2}{-7} \to \\\\ x^{2} = \frac{2}{7} \to \\\\ x=\pm \sqrt{\frac{2}{7}} \\\\\\\\ S= \left \{ -\sqrt{\frac{2}{7}};\sqrt{\frac{2}{7}}\left \}$