\[\frac{1^{\backslash x} - \frac{6}{x}}{\frac{12x - 36}{x} - x^{\backslash x}} =\]
\[= \frac{\frac{x - 6}{x}}{\frac{12x - 36 - x^{2}}{x}} =\]
\[= \frac{x - 6}{x}\ :\frac{12x - 36 - x^{2}}{x} =\]
\[= \frac{x - 6}{- \left( x^{2} - 12x + 36 \right)} =\]
\[= - \frac{1}{x - 6} = \frac{1}{6 - x}\]