| 3 | ( | x | + | 5 | ) | − | 6 | = | 5 | ( | 2 | x | − | 7 | ) | + | 2 |
| 方程左边 = | 3 | x | + | 3 | × | 5 | − | 6 |
| = | 3 | x | + | 15 | − | 6 |
| = | 3 | x | + | 9 |
| 3 | x | + | 9 | = | 5 | ( | 2 | x | − | 7 | ) | + | 2 |
| 方程右边 = | 5 | × | 2 | x | − | 5 | × | 7 | + | 2 |
| = | 10 | x | − | 35 | + | 2 |
| = | 10 | x | − | 33 |
| 3 | x | + | 9 | = | 10 | x | − | 33 |
| 3 | x | − | 10 | x | = | - | 33 | − | 9 |
| - | 7 | x | = | - | 33 | − | 9 |
| - | 7 | x | = | - | 42 |
| 42 | = | 7 | x |
| 7 | x | = | 42 |
| x | = | 42 | ÷ | 7 |
| = | 42 | × | 1 7 |
| = | 6 | × | 1 |
| x | = | 6 |