40 100 | x | + | 75 100 | ( | 700 | − | x | ) | = | 700 | × | 60 100 |
| 方程左边 = | 40 100 | x | + | 75 100 | × | 700 | − | 75 100 | x |
| = | 40 100 | x | + | 525 | − | 75 100 | x |
| = | - | 7 20 | x | + | 525 |
| - | 7 20 | x | + | 525 | = | 700 | × | 60 100 |
| 方程右边 = | 420 |
| - | 7 20 | x | + | 525 | = | 420 |
| - | 7 20 | x | = | 420 | − | 525 |
| - | 7 20 | x | = | - | 105 |
| 105 | = | 7 20 | x |
7 20 | x | = | 105 |
| x | = | 105 | ÷ | 7 20 |
| = | 105 | × | 20 7 |
| = | 15 | × | 20 |
| x | = | 300 |