TeX Quellcode:

\begin{array}{crcrcrcrcl} \text{II} & \dfrac{1}{9}a &+& \dfrac{1}{3}b &+& 0 &=& -\dfrac{1}{3} \cr \text{III} & \dfrac{4}{9}a &+& \dfrac{2}{3}b &+& 0 &=& 0 \cr \cr \text{II} & \dfrac{1}{9}a &+& \dfrac{1}{3}b & & &=& -\dfrac{1}{3} \cr \text{III} & \dfrac{4}{9}a &+& \dfrac{2}{3}b & & &=& 0 \end{array}