| 200 | − | 120 | × | 10 | − | ( | X | + | 5600 | ) | = | 0 |
| Left side of the equation = | 200 | − | 1200 | − | ( | X | + | 5600 | ) |
| = | - | 1000 | − | ( | X | + | 5600 | ) |
| - | 1000 | − | ( | X | + | 5600 | ) | = | 0 |
| Left side of the equation = | - | 1000 | − | X | − | 5600 |
| = | - | 6600 | − | X |
| - | 6600 | − | X | = | 0 |
| - | X | = | 0 | + | 6600 |
| - | X | = | 6600 |
| - | 6600 | = | X |
| X | = | - | 6600 |