Evaluate:|12 5 -2|

Question

|-3 0 1|
|-5 4 2|

It's going to be really confusing if I post my work. I got -127 from all the confusing things I did

Answer 1

12 5 -2

-3 0 1

-5 4 2

Expand the determinant along the second row:

3 times det of

5 -2

4 2

= 3* 18 = 54

-1 times det of

12 5

-5 4

= -73

54 - 73 = -19