| 3 | × | 4 | + | 6 | ( | - | 1 | ) | = | 3 | ( | - | 3 | ) | + | 6 | x |
| 方程左边 = | 12 | + | 6 | ( | - | 1 | ) |
| 12 | + | 6 | ( | - | 1 | ) | = | 3 | ( | - | 3 | ) | + | 6 | x |
| 方程左边 = | 12 | − | 6 | × | 1 |
| = | 12 | − | 6 |
| = | 6 |
| 6 | = | 3 | ( | - | 3 | ) | + | 6 | x |
| 方程右边 = | - | 3 | × | 3 | + | 6 | x |
| = | - | 9 | + | 6 | x |
| 6 | = | - | 9 | + | 6 | x |
| - | 6 | x | = | - | 9 | − | 6 |
| - | 6 | x | = | - | 15 |
| 15 | = | 6 | x |
| 6 | x | = | 15 |
| x | = | 15 | ÷ | 6 |
| = | 15 | × | 1 6 |
| = | 5 | × | 1 2 |
| x | = | 5 2 |
| x | = | 2.5 |