1139 2500 | ( | 5 | − | 4 | x | ) | = | 15 | − | x |
| 方程左边 = | 1139 2500 | × | 5 | − | 1139 2500 | × | 4 | x |
| = | 1139 500 | − | 1139 625 | x |
1139 500 | − | 1139 625 | x | = | 15 | − | x |
| - | 1139 625 | x | + | x | = | 15 | − | 1139 500 |
| - | 514 625 | x | = | 15 | − | 1139 500 |
| - | 514 625 | x | = | 6361 500 |
| - | 6361 500 | = | 514 625 | x |
514 625 | x | = | - | 6361 500 |
| x | = | - | 6361 500 | ÷ | 514 625 |
| = | - | 6361 500 | × | 625 514 |
| = | - | 6361 4 | × | 5 514 |
| x | = | - | 31805 2056 |
| x | = | - 15.469358 |