| - | 16 | ( | 3 | x | + | 5 | ) | + | 12 | ( | 2 | x | − | 4 | ) | + | 9 | = | 1 |
| 方程左边 = | - | 16 | × | 3 | x | − | 16 | × | 5 | + | 12 | ( | 2 | x | − | 4 | ) | + | 9 |
| = | - | 48 | x | − | 80 | + | 12 | ( | 2 | x | − | 4 | ) | + | 9 |
| = | - | 48 | x | − | 71 | + | 12 | ( | 2 | x | − | 4 | ) |
| = | - | 48 | x | − | 71 | + | 12 | × | 2 | x | − | 12 | × | 4 |
| = | - | 48 | x | − | 71 | + | 24 | x | − | 48 |
| = | - | 24 | x | − | 119 |
| - | 24 | x | − | 119 | = | 1 |
| - | 24 | x | = | 1 | + | 119 |
| - | 24 | x | = | 120 |
| - | 120 | = | 24 | x |
| 24 | x | = | - | 120 |
| x | = | - | 120 | ÷ | 24 |
| = | - | 120 | × | 1 24 |
| = | - | 5 | × | 1 |
| x | = | - | 5 |