| ( | 29 | − | 2 | x | ) | ( | 22 | − | 2 | x | ) | = | 29 | × | 22 | × | 3 4 |
| 方程左边 = | 29 | ( | 22 | − | 2 | x | ) | − | 2 | x | ( | 22 | − | 2 | x | ) |
| = | 29 | × | 22 | − | 29 | × | 2 | x | − | 2 | x | ( | 22 | − | 2 | x | ) |
| = | 638 | − | 58 | x | − | 2 | x | ( | 22 | − | 2 | x | ) |
| = | 638 | − | 58 | x | − | 2 | x | × | 22 | + | 2 | x | × | 2 | x |
| = | 638 | − | 58 | x | − | 44 | x | + | 4 | x | x |
| = | 638 | − | 102 | x | + | 4 | x | x |
| 638 | − | 102 | x | + | 4 | x | x | = | 29 | × | 22 | × | 3 4 |
| 方程右边 = | 957 2 |
| 638 | − | 102 | x | + | 4 | x | x | = | 957 2 |