\[x^{3} + 4x^{2} + 5x + 2 = 0\]
\[\left( x^{3} + x^{2} \right) + \left( 3x^{2} + 3x \right) + (2x + 2) = 0\]
\[x^{2}(x + 1) + 3x(x + 1) + 2(x + 1) = 0\]
\[(x + 1)\left( x^{2} + 3x + 2 \right) = 0\]
\[1)\ x + 1 = 0\]
\[x = - 1.\]
\[2)\ x^{2} + 3x + 2 = 0\]
\[x_{1} + x_{2} = - 3;\ \ x_{1} \cdot x_{2} = 2\]
\[x_{1} = - 2;x_{2} = - 1.\]
\[Ответ:x = - 1;x = - 2.\]