| X | ÷ | 200 | + | ( | 90 | − | X | ) | ÷ | 255 2 | = | 283 500 |
| 方程左边 = | 1 200 | X | + | 90 | × | 2 255 | − | X | × | 2 255 |
| = | 1 200 | X | + | 12 17 | − | X | × | 2 255 |
| = | - | 29 10200 | X | + | 12 17 |
| - | 29 10200 | X | + | 12 17 | = | 283 500 |
| - | 29 10200 | X | = | 283 500 | − | 12 17 |
| - | 29 10200 | X | = | - | 1189 8500 |
1189 8500 | = | 29 10200 | X |
29 10200 | X | = | 1189 8500 |
| X | = | 1189 8500 | ÷ | 29 10200 |
| = | 1189 8500 | × | 10200 29 |
| = | 41 5 | × | 6 |
| X | = | 246 5 |
| X | = | 49.2 |