1 2 | × | 100 | + | ( | x | − | 100 | ) | × | 2 5 | = | 11 25 |
| 方程左边 = | 50 | + | ( | x | − | 100 | ) | × | 2 5 |
| 50 | + | ( | x | − | 100 | ) | × | 2 5 | = | 11 25 |
| 方程左边 = | 50 | + | x | × | 2 5 | − | 100 | × | 2 5 |
| = | 50 | + | x | × | 2 5 | − | 40 |
| = | 10 | + | 2 5 | x |
| 10 | + | 2 5 | x | = | 11 25 |
2 5 | x | = | 11 25 | − | 10 |
2 5 | x | = | - | 239 25 |
| x | = | - | 239 25 | ÷ | 2 5 |
| = | - | 239 25 | × | 5 2 |
| = | - | 239 5 | × | 1 2 |
| x | = | - | 239 10 |
| x | = | - 23.9 |