\[\frac{x - 1}{3x - 12} - \frac{x - 3}{2x - 8} =\]
\[= \frac{x - 1^{\backslash 2}}{3(x - 4)} - \frac{x - 3^{\backslash 3}}{2(x - 4)} =\]
\[= \frac{2x - 2 - 3x + 9}{6(x - 4)} = \frac{7 - x}{6x - 24}.\]