| 3 | ( | 7 | ÷ | 8 | ) | − | 2 | ( | x | − | 7 | ÷ | 8 | ) | = | - | 6 | ( | x | + | 7 | ÷ | 8 | ) |
| 方程左边 = | 3 | × | 7 | ÷ | 8 | − | 2 | ( | x | − | 7 | ÷ | 8 | ) |
| = | 21 8 | − | 2 | ( | x | − | 7 | ÷ | 8 | ) |
| = | 21 8 | − | 2 | x | + | 2 | × | 7 | ÷ | 8 |
| = | 21 8 | − | 2 | x | + | 7 4 |
| = | 35 8 | − | 2 | x |
35 8 | − | 2 | x | = | - | 6 | ( | x | + | 7 | ÷ | 8 | ) |
| 方程右边 = | - | 6 | x | − | 6 | × | 7 | ÷ | 8 |
| = | - | 6 | x | − | 21 4 |
35 8 | − | 2 | x | = | - | 6 | x | − | 21 4 |
| - | 2 | x | + | 6 | x | = | - | 21 4 | − | 35 8 |
| 4 | x | = | - | 21 4 | − | 35 8 |
| 4 | x | = | - | 77 8 |
| x | = | - | 77 8 | ÷ | 4 |
| = | - | 77 8 | × | 1 4 |
| x | = | - | 77 32 |
| x | = | - 2.40625 |