TeX Quellcode:

\begin{array}{crcrcrcrl} \text{I} & 7x &+& 5y &-& 10z &=& 12 \cr \text{II} & -28x &-& 35y &+& 16z &=& -23 \cr \text{III} & -21x &-& 30y &+& 6z &=& 9 \cr \cr \text{I} & 7x &+& 5y &-& 10z &=& 12 \cr \text{4 I+II} & & & -15y &-& 24z &=& 25 \cr \text{3I+III} & & & -15y &-& 24z &=& 45 \cr \cr \text{I} & 7x &+& 5y &-& 10z &=& 12 \cr \text{II'} & & & -15y &-& 24z &=& 25 \cr \text{II'-III'} & & & & & 0 &=& -20 \end{array}