| - | 4 | ( | - | 5 | ÷ | ( | - | x | − | 4 | ) | + | 2 | ) | − | 2 | = | 10 |
| 4 | × | 5 | ÷ | ( | - | x | − | 4 | ) | − | 4 | × | 2 | − | 2 | = | 10 |
| 20 | ÷ | ( | - | x | − | 4 | ) | − | 8 | − | 2 | = | 10 |
| 20 | ÷ | ( | - | x | − | 4 | ) | − | 10 | = | 10 |
| 方程两边同时乘以: | ( | - | x | − | 4 | ) |
| 20 | − | 10 | ( | - | x | − | 4 | ) | = | 10 | ( | - | x | − | 4 | ) |
| 20 | + | 10 | x | + | 10 | × | 4 | = | 10 | ( | - | x | − | 4 | ) |
| 20 | + | 10 | x | + | 10 | × | 4 | = | - | 10 | x | − | 10 | × | 4 |
| 20 | + | 10 | x | + | 40 | = | - | 10 | x | − | 40 |
| 60 | + | 10 | x | = | - | 10 | x | − | 40 |
| 10 | x | + | 10 | x | = | - | 40 | − | 60 |
| 20 | x | = | - | 40 | − | 60 |
| 20 | x | = | - | 100 |
| x | = | - | 100 | ÷ | 20 |
| = | - | 100 | × | 1 20 |
| = | - | 5 | × | 1 |
| x | = | - | 5 |