\[\frac{x^{2} - 6x + 9}{2x - 6} = \frac{(x - 3)^{2}}{2(x - 3)} = \frac{x - 3}{2};\]
\[x = - 1:\]
\[\frac{- 1 - 3}{2} = - \frac{4}{2} = - 2.\]
\[Ответ:\ - 2.\]