| 10 | X | − | 120 | × | 10 | − | ( | 1200 | + | 560 | × | 10 | ) | = | 0 |
| Left side of the equation = | 10 | X | − | 1200 | − | ( | 1200 | + | 560 | × | 10 | ) |
| 10 | X | − | 1200 | − | ( | 1200 | + | 560 | × | 10 | ) | = | 0 |
| Left side of the equation = | 10 | X | − | 1200 | − | 1200 | − | 560 | × | 10 |
| = | 10 | X | − | 1200 | − | 1200 | − | 5600 |
| = | 10 | X | − | 8000 |
| 10 | X | − | 8000 | = | 0 |
| 10 | X | = | 0 | + | 8000 |
| 10 | X | = | 8000 |
| X | = | 8000 | ÷ | 10 |
| = | 8000 | × | 1 10 |
| = | 800 | × | 1 |
| X | = | 800 |