2+r1,r3-2r4,r4-r1
1 1 -1 2
0 0 -5 3
0 0 -14 -3
0 1 5 0
r2r3,c3c4 (交换两次,行列式值不变)
1 1 2 -1
0 1 0 5
0 0 -3 -14
0 0 3 -5
r4+r3
1 1 2 -1
0 1 0 5
0 0 -3 -5
0 0 0 -19
行列式 = 3*19 = 57.
2+r1,r3-2r4,r4-r1
1 1 -1 2
0 0 -5 3
0 0 -14 -3
0 1 5 0
r2r3,c3c4 (交换两次,行列式值不变)
1 1 2 -1
0 1 0 5
0 0 -3 -14
0 0 3 -5
r4+r3
1 1 2 -1
0 1 0 5
0 0 -3 -5
0 0 0 -19
行列式 = 3*19 = 57.