| 5 6 | A = | | | -8 3 |
x + 5y - z = 0, x + 5y - z = 3, x + 3y + z = 0, x + 3y + z = -3, x + 4y = 1. x + 4y = 0.
| 7 8 | A = | | | -4 5 |
3x + y + z = 0, 3x + y + z = -1, 5x + y - z = 0, 5x + y - z = 1, 4x + y = 2. 4x + y = 0.
| 3 -8 | A = | | | 7 4 |
x + 5y + z = 0, x + 5y + z = 1, -x + 3y + z = 0, -x + 3y + z = -1, 4y + z = 3. 4y + z = 0.
| 9 -6 | A = | | | 5 7 |
-x + 2y + z = 0, -x + 2y + z = 4, x + 8y + z = 0, x + 8y + z = -4, 5y + z = 1. 5y + z = 0.