Question

$- {x}^{3} + 3x + 2 = 0$
решите пожалуйста​

Answer 1

Ответ:

$- {x}^{3} + 3x + 2 = 0 \\ {x}^{3} - 3x - 2 = 0 \\ {x}^{3} - x - 2x - 2 = 0 \\ x( {x}^{2} - 1) - 2(x + 1) = 0 \\ x(x - 1)(x + 1) - 2(x + 1) = 0 \\ (x + 1)( {x}^{2} - x - 2) = 0 \\ x + 1 = 0 \\ x1 = - 1 \\ {x}^{2} - x - 2 = 0 \\ d = 1 + 8 = 9 \\ x2 = \frac{ 1 + 3}{2} = 2\\ x3 = \frac{ 1 - 3}{2} = - 1$