1-r4,r3+r4
2 1 0 -1
1 1 0 -1
3 2 0 2
1 1 1 1
按第3列展开 D=(-1)^(4+3)*
2 1 -1
1 1 -1
3 2 2
c3+c2
2 1 0
1 1 0
3 2 4
D = -4*
2 1
1 1
= -4(2-1) = -4.
1-r4,r3+r4
2 1 0 -1
1 1 0 -1
3 2 0 2
1 1 1 1
按第3列展开 D=(-1)^(4+3)*
2 1 -1
1 1 -1
3 2 2
c3+c2
2 1 0
1 1 0
3 2 4
D = -4*
2 1
1 1
= -4(2-1) = -4.