TeX Quellcode:

\begin{array}{rclcll}\dfrac{x-7}{x-4} - \dfrac{2x-5}{x-2} & \leq & 0 \\\\\dfrac{(x-7)(x-2)}{(x-4)(x-2)} - \dfrac{(2x-5)(x-4)}{(x-2)(x-4)} & \leq & 0 \\\\\dfrac{x^2-2x-7x+14}{(x-2)(x-4)} - \dfrac{2x^2-8x-5x+20}{(x-2)(x-4)} & \leq & 0 \\\\\dfrac{x^2-9x+14}{(x-2)(x-4)} - \dfrac{2x^2-13x+20}{(x-2)(x-4)} & \leq & 0 \\\\\dfrac{x^2-9x+14-\left(2x^2-13x+20\right)}{(x-2)(x-4)} & \leq & 0 \\\\\dfrac{x^2-9x+14-2x^2+13x-20}{(x-2)(x-4)} & \leq & 0 \\\\\dfrac{-x^2+4x-6}{(x-2)(x-4)} & \leq & 0\end{array}