\[\frac{x^{2} - 64}{x^{2} - 11x + 24} =\]
\[= \frac{(x - 8)(x + 8)}{(x - 3)(x + 8)} = \frac{x - 8}{x - 3}\]
\[x^{2} - 11x + 24 = (x - 3)(x - 8)\]
\[x_{1} + x_{2} = 11;\ \ x_{1} \cdot x_{2} = 24\]
\[x_{1} = 3;\ \ x_{2} = 8.\]