TeX Quellcode:

\begin{array}{crclllcc} \text{II} & \dfrac{1}{9}a+\dfrac{1}{3}b &=& -\dfrac{1}{3} &\vert& \cdot (-2)\cr \text{III} & \dfrac{4}{9}a+\dfrac{2}{3}b &=& 0 \cr\cr \text{II} & -\dfrac{2}{9}a-\dfrac{2}{3}b &=& \dfrac{2}{3} \cr \text{III} & \dfrac{4}{9}a+\dfrac{2}{3}b &=& 0 \cr\cr \text{II+III} & \dfrac{2}{9}a-0b &=& \dfrac{2}{3} \cr & \dfrac{2}{9}a &=& \dfrac{2}{3} &\vert& : \dfrac{2}{9} \cr & a &=& 3 \cr\cr \text{a in III} & \dfrac{4}{9}\cdot 3+\dfrac{2}{3}b &=& 0 &\vert& -\dfrac{4}{3} \cr & \dfrac{2}{3}b &=& -\dfrac{4}{3} &\vert& :\dfrac{2}{3} \cr & b &=& -2 \end{array}