例3求解非齐次方程组的通解 x1-x2-x3+x4=0 x1-x2+x3-3x4=1 2-2x3+3x4=-1/2 解对增广矩阵B进行初等变换 1-110)(1-1-110 B=1-11-31 002-41 1-23-1/2丿(00-12-1/ 上页例３ 求解非齐次方程组的通解 . 2 3 1 2 3 1 0 1 2 3 4 1 2 3 4 1 2 3 4      - - + = - - + - = - - + = x x x x x x x x x x x x 解 对增广矩阵B进行初等变换           - - - - - - - = 1 1 2 3 1 2 1 1 1 3 1 1 1 1 1 0 B           - - - - - 0 0 1 2 1 2 0 0 2 4 1 1 1 1 1 0 ~