TeX Quellcode:

\begin{array}{rcl} \genfrac{}{}{1pt}{0}{11xyz^2}{\frac{7r^2 x}{-5rz^2}} &=& 11xyz^2 : \dfrac{7r^2 x}{-5rz^2} \\\\&=& 11xyz^2 \cdot \left(-\dfrac{5rz^2}{7r^2 x}\right) \\\\&=& 11yz^2 \cdot \left(-\dfrac{5z^2}{7r}\right) \\\\&=& -\dfrac{11yz^4}{7r} \end{array}