\[y = \sqrt{x^{2} - 5x - 14} - \frac{3}{x^{2} - 25}\]
\[\left\{ \begin{matrix}
x² - 5x - 14 \geq 0,\ \ x
eq \pm 5 \\
x²
eq 25\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \\
\end{matrix} \right.\ \]
\[x^{2} - 5x - 14 = 0\]
\[x_{1} + x_{2} = 5,\ \ x_{1} = 7\]
\[x_{1} \cdot x_{2} = - 14,\ \ x_{2} = - 2\]