| 3 | ( | 2 | ( | - | 3 | ( | 3 | x | + | 13 | ) | − | 12 | ) | + | 16 | ) | + | 6 | = | 5 | ( | 3 | x | + | 8 | ) | − | 85 |
| 方程左边 = | 3 | × | 2 | ( | - | 3 | ( | 3 | x | + | 13 | ) | − | 12 | ) | + | 3 | × | 16 | + | 6 |
| = | 6 | ( | - | 3 | ( | 3 | x | + | 13 | ) | − | 12 | ) | + | 48 | + | 6 |
| = | 6 | ( | - | 3 | ( | 3 | x | + | 13 | ) | − | 12 | ) | + | 54 |
| = | - | 6 | × | 3 | ( | 3 | x | + | 13 | ) | − | 6 | × | 12 | + | 54 |
| = | - | 18 | ( | 3 | x | + | 13 | ) | − | 72 | + | 54 |
| = | - | 18 | ( | 3 | x | + | 13 | ) | − | 18 |
| = | - | 18 | × | 3 | x | − | 18 | × | 13 | − | 18 |
| = | - | 54 | x | − | 234 | − | 18 |
| = | - | 54 | x | − | 252 |
| - | 54 | x | − | 252 | = | 5 | ( | 3 | x | + | 8 | ) | − | 85 |
| 方程右边 = | 5 | × | 3 | x | + | 5 | × | 8 | − | 85 |
| = | 15 | x | + | 40 | − | 85 |
| = | 15 | x | − | 45 |
| - | 54 | x | − | 252 | = | 15 | x | − | 45 |
| - | 54 | x | − | 15 | x | = | - | 45 | + | 252 |
| - | 69 | x | = | - | 45 | + | 252 |
| - | 69 | x | = | 207 |
| - | 207 | = | 69 | x |
| 69 | x | = | - | 207 |
| x | = | - | 207 | ÷ | 69 |
| = | - | 207 | × | 1 69 |
| = | - | 3 | × | 1 |
| x | = | - | 3 |