18 100 | x | + | ( | 1000 | − | x | ) | × | 23 100 | = | 500 | × | 20 100 |
| Left side of the equation = | 18 100 | x | + | 1000 | × | 23 100 | − | x | × | 23 100 |
| = | 18 100 | x | + | 230 | − | x | × | 23 100 |
| = | - | 1 20 | x | + | 230 |
| - | 1 20 | x | + | 230 | = | 500 | × | 20 100 |
| Right side of the equation = | 100 |
| - | 1 20 | x | + | 230 | = | 100 |
| - | 1 20 | x | = | 100 | − | 230 |
| - | 1 20 | x | = | - | 130 |
| 130 | = | 1 20 | x |
1 20 | x | = | 130 |
| x | = | 130 | ÷ | 1 20 |
| = | 130 | × | 20 |
| x | = | 2600 |