| 140 | − | ( | x | − | 6 | ) | ÷ | x | + | 10 | − | 140 | = | 3 | ÷ | 1 |
| 方程两边同时乘以: | x |
| 140 | x | − | ( | x | − | 6 | ) | + | 10 | x | − | 140 | x | = | 3 | ÷ | 1 | × | x |
| 140 | x | − | x | + | 6 | + | 10 | x | − | 140 | x | = | 3 | ÷ | 1 | × | x |
| 140 | x | − | x | + | 6 | + | 10 | x | − | 140 | x | = | 3 | x |
| 9 | x | + | 6 | = | 3 | x |
| 9 | x | − | 3 | x | = | - | 6 |
| 6 | x | = | - | 6 |
| x | = | - | 6 | ÷ | 6 |
| = | - | 6 | × | 1 6 |
| = | - | 1 | × | 1 |
| x | = | - | 1 |