求矩阵的秩 3-21 1-12 10-2

题目

求矩阵的秩 3-21 1-12 10-2

答案

3 -2 1
1 -1 2
1 0 -2
r1-3r2,r2-r3
0 1 -5
0 -1 4
1 0 -2
r2+r1
0 1 -5
0 0 -1
1 0 -2
r(A) = 3.