| 56 | − | x | − | ( | 580 | + | 40 | − | x | ) | − | ( | 56 | − | x | − | 13 100 | − | 5 | − | x | ) | − | 12 100 | = | 120 |
| Left side of the equation = | 1397 25 | − | x | − | ( | 580 | + | 40 | − | x | ) | − | ( | 56 | − | x | − | 13 100 | − | 5 | − | x | ) |
1397 25 | − | x | − | ( | 580 | + | 40 | − | x | ) | − | ( | 56 | − | x | − | 13 100 | − | 5 | − | x | ) | = | 120 |
| Left side of the equation = | 1397 25 | − | x | − | 580 | − | 40 | + | x | − | ( | 56 | − | x | − | 13 100 | − | 5 | − | x | ) |
| = | - | 14103 25 | − | 0 | x | − | ( | 56 | − | x | − | 13 100 | − | 5 | − | x | ) |
| = | - | 14103 25 | − | 0 | x | − | 56 | + | x | + | 13 100 | + | 5 | + | x |
| = | - | 61499 100 | + | 2 | x |
| - | 61499 100 | + | 2 | x | = | 120 |
| 2 | x | = | 120 | + | 61499 100 |
| 2 | x | = | 73499 100 |
| x | = | 73499 100 | ÷ | 2 |
| = | 73499 100 | × | 1 2 |
| x | = | 73499 200 |
| x | = | 367.495 |