| 8 | ( | 3 | − | x | ) | × | 2 | − | 72 | = | 0 |
| 方程左边 = | 16 | ( | 3 | − | x | ) | − | 72 |
| 16 | ( | 3 | − | x | ) | − | 72 | = | 0 |
| 方程左边 = | 16 | × | 3 | − | 16 | x | − | 72 |
| = | 48 | − | 16 | x | − | 72 |
| = | - | 24 | − | 16 | x |
| - | 24 | − | 16 | x | = | 0 |
| - | 16 | x | = | 0 | + | 24 |
| - | 16 | x | = | 24 |
| - | 24 | = | 16 | x |
| 16 | x | = | - | 24 |
| x | = | - | 24 | ÷ | 16 |
| = | - | 24 | × | 1 16 |
| = | - | 3 | × | 1 2 |
| x | = | - | 3 2 |
| x | = | - 1.5 |