\[ax < 6x - 9\]
\[ax - 6x < - 9\]
\[(a - 6)x < - 9\]
\[x < \frac{- 9}{a - 6}\]
\[Нет\ решения\ \]
\[при\ a - 6 = 0 \Longrightarrow a = 6.\]
\[Ответ:\ \ при\ a = 6.\]