TeX Quellcode:

\begin{array}{crcrcrcrl} \text{I} & -18x &-& 4y &-& 26z &=& 4 \cr \text{II} & 9x &+& 8y &+& 13z &=& -5 \cr \text{III} & 9x &-& 12y &+& 7z &=& 11 \cr \cr \text{I} & -18x &-& 4y &-& 26z &=& 4 \cr \text{I+2 II} & & & 12y & & &=& -6 & \Rightarrow y = -\dfrac{1}{2} \cr \text{I+2 III} & & & -28y &-& 12z &=& 26 \cr \cr \cr y =-\frac{1}{2} \text{ in III'} & & & -28\cdot \left(-\dfrac{1}{2}\right) &-& 12z &=& 26 & \Rightarrow z = -1 \cr \cr y =-\frac{1}{2} \text{ und }z = -1 \text{ in I} & -18x &-& 4 \cdot \left(-\dfrac{1}{2}\right) &-& 26 \cdot \left(-1\right) &=& 4 & \Rightarrow x = \dfrac{4}{3} \end{array}