for each final matrix, state the solution.

1 0 0 | 3
0 1 0 | -1
0 0 1 | 8

1 0 -6 | 11
0 1 4 | 7
0 0 0 | -2

1 0 2 | 9
0 1 -8 | 5
0 0 0 | 0