0 0 1 0
0 2 0 0 r1 <->r2
0 0 0 3 r3 <-> r4
4 0 0 0
=
0 2 0 0
0 0 1 0 r1<->r3
4 0 0 0
0 0 0 3
=-
4 0 0 0
0 0 1 0
0 2 0 0 r2<->r3
0 0 0 3
=
4 0 0 0
0 2 0 0
0 0 1 0
0 0 0 3
=4x2x1x3=24
原式=4×(-1)^(4+1)×1×(-1)^(1+3)×2×(-1)^(2+2)×3×(-1)^(3+4)
=-4×1×2×(-3)
=24
4