TeX Quellcode:

\begin{array}{rcl} \genfrac{}{}{1pt}{0}{-\frac{63x^2 y^3}{4z}}{\frac{7x^3 \cdot 3z^{23}}{z}} &=& -\dfrac{63x^2 y^3}{4z} : \dfrac{7x^3 \cdot 3z^{23}}{z} \\\\ &=& -\dfrac{63x^2 y^3}{4z} \cdot \dfrac{z}{21x^3 z^{23}} \\\\ &=& -\dfrac{3 y^3}{4} \cdot \dfrac{1}{x z^{23}} \\\\&=& -\dfrac{3y^3}{4xz^{23}} \end{array}