$ \begin{array}{l} \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 1 & 1 & 1 & 0 \\ 2 & { - 2} & { - 5} & 0 \\ 3 & 0 & 1 & 1 \\ 4 & { - 2} & { - 3} & 1 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 6 \\ { - 13} \\ {13} \\ 1 \\ \end{array}} \\ \end{array}} \right) \\ R2 - 2R1 \to R2 \\ R3 - 3R1 \to R3 \\ R4 - 4R1 \to R4 \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 1 & 1 & 1 & 0 \\ 0 & { - 4} & { - 7} & 0 \\ 0 & { - 3} & { - 2} & 1 \\ 0 & { - 6} & { - 7} & 1 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 6 \\ { - 25} \\ { - 5} \\ { - 23} \\ \end{array}} \\ \end{array}} \right) \\ 4R3 - 3R2 \to R3 \\ 2R4 - 3R2 \to R4 \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 1 & 1 & 1 & 0 \\ 0 & { - 4} & { - 7} & 0 \\ 0 & 0 & {13} & 4 \\ 0 & 0 & 7 & 2 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 6 \\ { - 25} \\ {55} \\ {29} \\ \end{array}} \\ \end{array}} \right) \\ 13R4 - 7R3 \to R4 \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 1 & 1 & 1 & 0 \\ 0 & { - 4} & { - 7} & 0 \\ 0 & 0 & {13} & 4 \\ 0 & 0 & 0 & { - 2} \\ \end{array}} \right|} & {\begin{array}{*{20}c} 6 \\ { - 25} \\ {55} \\ { - 8} \\ \end{array}} \\ \end{array}} \right) \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 1 & 1 & 1 & 0 \\ 0 & { - 4} & { - 7} & 0 \\ 0 & 0 & {13} & 4 \\ 0 & 0 & 0 & 1 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 6 \\ { - 25} \\ {55} \\ 4 \\ \end{array}} \\ \end{array}} \right) \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 1 & 1 & 1 & 0 \\ 0 & { - 4} & { - 7} & 0 \\ 0 & 0 & {13} & 0 \\ 0 & 0 & 0 & 1 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 6 \\ { - 25} \\ {39} \\ 4 \\ \end{array}} \\ \end{array}} \right) \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 1 & 1 & 1 & 0 \\ 0 & { - 4} & { - 7} & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 6 \\ { - 25} \\ 3 \\ 4 \\ \end{array}} \\ \end{array}} \right) \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 1 & 1 & 1 & 0 \\ 0 & { - 4} & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 6 \\ { - 4} \\ 3 \\ 4 \\ \end{array}} \\ \end{array}} \right) \\ \left( {\begin{array}{*{20}c} {\left. {\begin{array}{*{20}c} 1 & 0 & 0 & 0 \\ 0 & 1 & 0 & 0 \\ 0 & 0 & 1 & 0 \\ 0 & 0 & 0 & 1 \\ \end{array}} \right|} & {\begin{array}{*{20}c} 2 \\ 1 \\ 3 \\ 4 \\ \end{array}} \\ \end{array}} \right) \\ \end{array} $
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