1 3 1 0
2 5 0 1

1 3 1 0
0 -1 -2 1

1 3 1 0
0 1 2 -1

1 0 -5 3
0 1 2 -1

1__3__*__-5__3__=__1__0
2__5__ ___2__-1__ __0__1