Question

求解一道4阶行列式,要详细过程（拍照最好）

Answer 1

c2+2c1,c3+c1,c4-4c1

5 14 7 -19

2 7 3 -10

-5 -17 -8 29

1 0 0 0

按第4行展开

= (-1)^(4+1)*

14 7 -19

7 3 -10

-17 -8 29

r3+r1

14 7 -19

7 3 -10

-3 -1 10

c1-3c2,c3+10c2

-7 7 51

-2 3 20

0 -1 0

= -(-1)*(-1)^(3+2)*

-7 51

-2 20

= - (-140+102)

= 38