所有的行都加到第一行上去得
原式=
| 6 6 6 6 |
| 1 1 1 3 |
| 3 1 1 1 |
| 1 3 1 1 |
=
| 1 1 1 1 |
| 1 1 1 3 | *6
| 3 1 1 1 |
| 1 3 1 1 | 每一行都减掉第一行
=
| 1 1 1 1 |
| 0 0 0 2 | *6
| 2 0 0 0 |
| 0 2 0 0 |按最后一行展开
=
| 1 1 1 |
| 0 0 2 | *2*(-1)^(4+2)*6
| 2 0 0 |
=
| 1 1 |
| 0 2 | *2*(-1)^(3+1)*2*6
=48