| 2 | ( | 3 | ( | 4 | ( | 5 | x | − | 1 | ) | − | 8 | ) | − | 20 | ) | − | 7 | = | 1 |
| 方程左边 = | 2 | × | 3 | ( | 4 | ( | 5 | x | − | 1 | ) | − | 8 | ) | − | 2 | × | 20 | − | 7 |
| = | 6 | ( | 4 | ( | 5 | x | − | 1 | ) | − | 8 | ) | − | 40 | − | 7 |
| = | 6 | ( | 4 | ( | 5 | x | − | 1 | ) | − | 8 | ) | − | 47 |
| = | 6 | × | 4 | ( | 5 | x | − | 1 | ) | − | 6 | × | 8 | − | 47 |
| = | 24 | ( | 5 | x | − | 1 | ) | − | 48 | − | 47 |
| = | 24 | ( | 5 | x | − | 1 | ) | − | 95 |
| = | 24 | × | 5 | x | − | 24 | × | 1 | − | 95 |
| = | 120 | x | − | 24 | − | 95 |
| = | 120 | x | − | 119 |
| 120 | x | − | 119 | = | 1 |
| 120 | x | = | 1 | + | 119 |
| 120 | x | = | 120 |
| x | = | 120 | ÷ | 120 |
| = | 120 | × | 1 120 |
| = | 1 | × | 1 |
| x | = | 1 |