\[Пусть\ \ t = x^{2} + 3x - 1:\]
\[t^{2} - 12t + 27 = 0\]
\[t_{1} + t_{2} = 12;\ \ t_{1} \cdot t_{2} = 27\]
\[t_{1} = 9,\ \ t_{2} = 3.\]