3 -3 -2 -5
2 5 4 6
5 5 8 7
4 4 5 6
r3-r4
3 -3 -2 -5
2 5 4 6
1 1 3 1
4 4 5 6
r1-3r3,r2-2r3,r4-4r3
0 -6 -11 -8
0 3 -2 4
1 1 3 1
0 0 -7 2
r1+2r2
0 0 -15 0
0 3 -2 4
1 1 3 1
0 0 -7 2
= (-1)^t(3214) * 1*3*(-15)*2
= 90.