| x | + | 127 100 | ( | 10 | − | x | ) | = | 12 |
| 方程左边 = | x | + | 127 100 | × | 10 | − | 127 100 | x |
| = | x | + | 127 10 | − | 127 100 | x |
| = | - | 27 100 | x | + | 127 10 |
| - | 27 100 | x | + | 127 10 | = | 12 |
| - | 27 100 | x | = | 12 | − | 127 10 |
| - | 27 100 | x | = | - | 7 10 |
7 10 | = | 27 100 | x |
27 100 | x | = | 7 10 |
| x | = | 7 10 | ÷ | 27 100 |
| = | 7 10 | × | 100 27 |
| = | 7 | × | 10 27 |
| x | = | 70 27 |
| x | = | 2.592593 |