| ( | 1 | − | 2 | x | ) | ÷ | 3 | = | ( | 3 | x | + | 1 | ) | ÷ | 7 | − | 2 |
| 方程左边 = | 1 | × | 1 3 | − | 2 | x | × | 1 3 |
| = | 1 3 | − | 2 3 | x |
1 3 | − | 2 3 | x | = | ( | 3 | x | + | 1 | ) | ÷ | 7 | − | 2 |
| 方程右边 = | 3 | x | × | 1 7 | + | 1 | × | 1 7 | − | 2 |
| = | 3 7 | x | + | 1 7 | − | 2 |
| = | 3 7 | x | − | 13 7 |
1 3 | − | 2 3 | x | = | 3 7 | x | − | 13 7 |
| - | 2 3 | x | − | 3 7 | x | = | - | 13 7 | − | 1 3 |
| - | 23 21 | x | = | - | 13 7 | − | 1 3 |
| - | 23 21 | x | = | - | 46 21 |
46 21 | = | 23 21 | x |
23 21 | x | = | 46 21 |
| x | = | 46 21 | ÷ | 23 21 |
| = | 46 21 | × | 21 23 |
| = | 2 | × | 1 |
| x | = | 2 |