| 20 | + | 3 10 | x | = | ( | 1000 | + | x | − | 600 | ) | × | 50 100 |
| 方程右边 = | 1000 | × | 50 100 | + | x | × | 50 100 | − | 600 | × | 50 100 |
| = | 500 | + | x | × | 50 100 | − | 300 |
| = | 200 | + | 50 100 | x |
| 20 | + | 3 10 | x | = | 200 | + | 50 100 | x |
3 10 | x | − | 50 100 | x | = | 200 | − | 20 |
| - | 1 5 | x | = | 200 | − | 20 |
| - | 1 5 | x | = | 180 |
| - | 180 | = | 1 5 | x |
1 5 | x | = | - | 180 |
| x | = | - | 180 | ÷ | 1 5 |
| = | - | 180 | × | 5 |
| x | = | - | 900 |