| 160 | − | x | ( | x | + | 12 | ) | − | ( | x | + | 12 | ) | ( | x | + | 12 | ) | = | 0 |
| 方程左边 = | 160 | − | x | x | − | x | × | 12 | − | ( | x | + | 12 | ) | ( | x | + | 12 | ) |
| = | 160 | − | x | x | − | 12 | x | − | x | ( | x | + | 12 | ) | − | 12 | ( | x | + | 12 | ) |
| = | 160 | − | x | x | − | 12 | x | − | x | x | − | x | × | 12 | − | 12 | ( | x | + | 12 | ) |
| = | 160 | − | x | x | − | 24 | x | − | x | x | − | 12 | ( | x | + | 12 | ) |
| = | 160 | − | x | x | − | 24 | x | − | x | x | − | 12 | x | − | 12 | × | 12 |
| = | 160 | − | x | x | − | 24 | x | − | x | x | − | 12 | x | − | 144 |
| = | 16 | − | x | x | − | 36 | x | − | x | x |
| 16 | − | x | x | − | 36 | x | − | x | x | = | 0 |