TeX Quellcode:

\begin{array}{crcrcrcrl} \text{I} & 8x &+& 9y &-& 5z &=& -9 \cr \text{II} & -6x &-& 3y &+& 5z &=& -27 \cr \text{III} & \frac{1}{2}x &+& y &-& 2z &=& -10 \cr \cr \text{I} & 8x &+& 9y &-& 5z &=& -9 \cr \text{3 I+4 II} & & & 15y &+& 5z &=& -135 \cr \text{I-16 III} & & & -7y &+& 27z &=& 151 \cr \cr \text{I} & 8x &+& 9y &-& 5z &=& -9 \cr \text{II'} & & & 15y &+& 5z &=& -135 \cr \text{7 II'+15 III'} & & & & & 440z &=& 1320 & \Rightarrow z = 3 \cr \cr z = 3 \text{ in II'} & & & 15y &+& 5 \cdot 3 &=& -135 & \Rightarrow y = -10 \cr z = 3 \text{ und } y = -10 \text{ in I} & 8x &+& 9 \cdot \left(-10\right) &-& 5 \cdot 3 &=& -9 & \Rightarrow x = 12 \end{array}