Question 1129413

[0 0 4 6]
[2 1 1 3]
[2 1 2 3]
[3 0 1 7]

We start from the first row and we get:
4* [2 1 3]  
   [2 1 3]
   [3 0 7]
6* [2 1 1]  
   [2 1 2]
   [3 0 1]
again from last row for the first term
3*0 + 7*0 = 0
same for the second term

3*1 + 0 = 3
Now for the sign: it's minus

so I find -3.