\[\sqrt{9 - 15x} + \frac{3}{x^{2} - 1}\]
\[9 - 15x \geq 0,\ \ x eq \pm 1\]
\[15x \leq 9\]
\[x \leq \frac{3}{5}\]
\[x \leq 0,6\]
\[Ответ:( - \infty;\ - 1) \cup \left( - 1;\frac{3}{5} \right\rbrack.\]