\[x^{3} - 3x^{2} - 3x + 9 = 0\]
\[x\left( x^{2} - 3 \right) - 3 \cdot \left( x^{2} - 3 \right) = 0\]
\[\left( x^{2} - 3 \right) - 3 \cdot \left( x^{2} - 3 \right) = 0\]
\[\left( x^{2} - 3 \right)(x - 3) = 0\]
\[\left( x - \sqrt{3} \right)\left( x + \sqrt{3} \right)(x - 3) = 0\]
\[Ответ:\sqrt{3};\ - \sqrt{3};\ 3.\]