| ( | 2 | d | + | 1 | ) | ( | d | + | 2 | ) | ( | d | + | 3 | ) | = | d | ( | d | + | 1 | ) | ( | 2 | d | + | 5 | ) |
| 方程左边 = | 2 | d | ( | d | + | 2 | ) | ( | d | + | 3 | ) | + | 1 | ( | d | + | 2 | ) | ( | d | + | 3 | ) |
| = | 2 | d | d | ( | d | + | 3 | ) | + | 2 | d | × | 2 | ( | d | + | 3 | ) | + | 1 | ( | d | + | 2 | ) | ( | d | + | 3 | ) |
| = | 2 | d | d | ( | d | + | 3 | ) | + | 4 | d | ( | d | + | 3 | ) | + | 1 | ( | d | + | 2 | ) | ( | d | + | 3 | ) |
| = | 2 | d | d | d | + | 2 | d | d | × | 3 | + | 4 | d | ( | d | + | 3 | ) | + | 1 |
| = | 2 | d | d | d | + | 6 | d | d | + | 4 | d | ( | d | + | 3 | ) | + | 1 | ( | d | + | 2 | ) |
| = | 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 4 | d |
| = | 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 12 | d |
| = | 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 12 | d |
| = | 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 12 | d |
| = | 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 12 | d |
| = | 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 12 | d |
| = | 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 15 | d |
| = | 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 15 | d |
| = | 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 15 | d |
| = | 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 17 | d |
| 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 17 | d | = | d | ( | d | + | 1 | ) | ( | 2 | d | + | 5 | ) |
| 方程右边 = | d | d | ( | 2 | d | + | 5 | ) | + | d | × | 1 | ( | 2 | d | + | 5 | ) |
| = | d | d | × | 2 | d | + | d | d | × | 5 | + | d | × | 1 | ( | 2 | d | + | 5 | ) |
| = | d | d | × | 2 | d | + | d | d | × | 5 | + | d | × | 1 | × | 2 | d | + | d |
| = | d | d | × | 2 | d | + | d | d | × | 5 | + | d | × | 2 | d | + | d | × | 5 |
| 2 | d | d | d | + | 6 | d | d | + | 4 | d | d | + | 17 | d | = | d | d | × | 2 | d | + | d | d | × | 5 | + | d | × | 2 | d | + | 5 | d |