利用初等行变换,将方程组增广矩阵[AB]化为阶梯阵再求解:
4 2 1 7 4 2 1 7
[A B]= 2 -5 2 -1 -> 0 12 -3 9
1 2 6 9 0 6 23 29
4 2 1 7 8 0 3 11
-> 0 4 -1 3 -> 0 4 -1 3
0 6 23 29 0 0 49 49
8 0 0 8 1 0 0 1
-> 0 4 0 4 -> 0 1 0 1
0 0 1 1 0 0 1 1
所以解为:
X1=1
X2=1
X3=1