2 -4 -3 5
-3 1 4 -2
7 2 5 3
4 -3 -2 6
r1+4r2,r3-2r2,r4+3r2
-10 0 13 -3
-3 1 4 -2
13 0 -3 7
-5 0 10 0
按第2列展开 D=
-10 13 -3
13 -3 7
-5 10 0
c2+2c1
-10 -7 -3
13 23 7
-5 0 0
= -5(-49+69)
= -100.
2 -4 -3 5
-3 1 4 -2
7 2 5 3
4 -3 -2 6
r1+4r2,r3-2r2,r4+3r2
-10 0 13 -3
-3 1 4 -2
13 0 -3 7
-5 0 10 0
按第2列展开 D=
-10 13 -3
13 -3 7
-5 10 0
c2+2c1
-10 -7 -3
13 23 7
-5 0 0
= -5(-49+69)
= -100.