Question

х³+2х²=х+2 решите уравнение

Answer 1

Ответ:

${x}^{3} + 2 {x}^{2} - x - 2 = 0$

${x}^{3} - x = x( {x}^{2} - 1)$

$2 {x}^{2} - 2 = 2( {x}^{2} - 1)$

$x( {x}^{2} - 1) + 2( {x}^{2} - 1) = 0$

$(x + 2) \times ( {x}^{2} - 1) = 0$

$x + 2 = 0 \\ x = - 2$

$x ^{2} - 1 = 0 \\ {x}^{2} = 1 \\ x = 1( - 1)$