Question

求这两道行列式做法！！！

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Answer 1

1. D = -A21 + 2A24, A21 =
| 2 3 4|
|-1 -4 0|
| 2 -1 5|
A21 =
| 2 -5 4|
|-1 0 0|
| 2 -9 5|
A21 =
|-5 4|
|-9 -5|
A21 = 61
A24 =
| 1 2 3|
| 3 -1 -4|
| 1 2 -1|
A24 =
| 1 2 3|
| 3 -1 -4|
| 0 0 -4|
A24 = (-4)(-1-6) = 28
D = -61 +2*28 = -5.

2. D =
|-1 0 1 6|
| 3 0 0 2|
| 1 1 1 -1|
| 4 0 1 2|
D = (-1)*
|-1 1 6|
| 3 0 2|
| 4 1 2|
D = (-1)*
|-1 1 6|
| 3 0 2|
| 5 0 -4|
D =
| 3 2|
| 5 -4|
D = -22

Answer 2

下载作业帮，里面可以解决