\[t = x^{2} - 2x + 3\]
\[(2t - 9)t - (5t - 12) = 0\]
\[2t^{2} - 9t - 5t + 12 = 0\]
\[2t^{2} - 14t + 12 = 0\ \ \ \ \ \ \ \ \ \ |\ :2\]
\[t^{2} - 7t + 6 = 0\]
\[D = ( - 7)^{2} - 4 \cdot 1 \cdot 6 =\]
\[= 49 - 24 = 25\]
\[t_{1} = \frac{7 + \sqrt{25}}{2} = \frac{7 + 5}{2} = \frac{12}{2} = 6\]
\[t_{2} = \frac{7 - \sqrt{25}}{2} = \frac{7 - 5}{2} = \frac{2}{2} = 1\]
\[1)\ x^{2} - 2x + 3 = 6\]
\[D = ( - 2)^{2} - 4 \cdot 1 \cdot ( - 3) =\]
\[= 4 + 12 = 16\]
\[x_{1} = \frac{2 + \sqrt{16}}{2} = \frac{2 + 4}{2} = \frac{6}{2} = 3\]
\[x_{2} = \frac{2 - \sqrt{16}}{2} = \frac{2 - 4}{2} = \frac{- 2}{2} =\]
\[= - 1\]
\[2)\ x^{2} - 2x + 3 = 1\]
\[x^{2} - 2x + 2 = 0\]
\[D = ( - 2)^{2} - 4 \cdot 1 \cdot 2 = 4 - 8 =\]
\[= - 4 < 0 \Longrightarrow нет\ решения.\]
\[Ответ:3;\ - 1.\]