uitgewerkt

$ \left\{ \begin{array}{l} 2x + 8y + 3z = 2 \\ x + 3y + 2z = 5 \\ 2x + 7y + 4z = 8 \\ \end{array} \right. $

$ \begin{array}{l} \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 2 & 8 & 3 \\ 1 & 3 & 2 \\ 2 & 7 & 4 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 2 \\ 5 \\ 8 \\ \end{array}} \\ \end{array}} \right) \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 2 & 8 & 3 \\ 0 & 2 & { - 1} \\ 0 & 1 & 0 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 2 \\ { - 8} \\ { - 2} \\ \end{array}} \\ \end{array}} \right) \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 2 & 8 & 3 \\ 0 & 0 & { - 1} \\ 0 & 1 & 0 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 2 \\ { - 4} \\ { - 2} \\ \end{array}} \\ \end{array}} \right) \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 2 & 8 & 3 \\ 0 & 0 & 1 \\ 0 & 1 & 0 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 2 \\ 4 \\ { - 2} \\ \end{array}} \\ \end{array}} \right) \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 2 & 0 & 0 \\ 0 & 0 & 1 \\ 0 & 1 & 0 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 6 \\ 4 \\ { - 2} \\ \end{array}} \\ \end{array}} \right) \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 1 & 0 & 0 \\ 0 & 0 & 1 \\ 0 & 1 & 0 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 3 \\ 4 \\ { - 2} \\ \end{array}} \\ \end{array}} \right) \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 3 \\ { - 2} \\ 4 \\ \end{array}} \\ \end{array}} \right) \\ \end{array} $

$ \left\{ \begin{array}{l} x = 3 \\ y = - 2 \\ z = 4 \\ \end{array} \right. $