D =
2,3,4行减第1行
3 1 1 1
-2 2 0 0
-2 0 2 0
-2 0 0 2
c1+c2+c3+c4
6 1 1 1
0 2 0 0
0 0 2 0
0 0 0 2
= 6*2^3 = 48.那加边法 又怎样啊D =1111103111013110113101113ri-r1, i=2,3,4,5 11111-12000-10200-10020-10002c1+(1/2)c2+(1/2)c3+(1/2)c3+(1/2)c33111102000002000002000002= 3*2^4 = 48