| 1 | ÷ | d | + | 1 | ÷ | ( | d | + | 3 | ) | + | 1 | ÷ | ( | d | + | 6 | ) | = | 0 |
| 方程两边同时乘以: | d |
| 1 | + | 1 | ÷ | ( | d | + | 3 | ) | × | d | + | 1 | ÷ | ( | d | + | 6 | ) | × | d | = | 0 |
| 方程两边同时乘以: | ( | d | + | 3 | ) |
| 1 | ( | d | + | 3 | ) | + | 1 | d | + | 1 | ÷ | ( | d | + | 6 | ) | × | d | ( | d | + | 3 | ) | = | 0 |
| 1 | d | + | 1 | × | 3 | + | 1 | d | + | 1 | ÷ | ( | d | + | 6 | ) | × | d | ( | d | + | 3 | ) | = | 0 |
| 1 | d | + | 3 | + | 1 | d | + | 1 | ÷ | ( | d | + | 6 | ) | × | d | ( | d | + | 3 | ) | = | 0 |
| 2 | d | + | 3 | + | 1 | ÷ | ( | d | + | 6 | ) | × | d | ( | d | + | 3 | ) | = | 0 |
| 方程两边同时乘以: | ( | d | + | 6 | ) |
| 2 | d | ( | d | + | 6 | ) | + | 3 | ( | d | + | 6 | ) | + | 1 | d | ( | d | + | 3 | ) | = | 0 |
| 2 | d | d | + | 2 | d | × | 6 | + | 3 | ( | d | + | 6 | ) | + | 1 | d | ( | d | + | 3 | ) | = | 0 |
| 2 | d | d | + | 12 | d | + | 3 | ( | d | + | 6 | ) | + | 1 | d | ( | d | + | 3 | ) | = | 0 |
| 2 | d | d | + | 12 | d | + | 3 | d | + | 3 | × | 6 | + | 1 | d | ( | d | + | 3 | ) | = | 0 |
| 2 | d | d | + | 12 | d | + | 3 | d | + | 18 | + | 1 | d | ( | d | + | 3 | ) | = | 0 |
| 2 | d | d | + | 15 | d | + | 18 | + | 1 | d | ( | d | + | 3 | ) | = | 0 |
| 2 | d | d | + | 15 | d | + | 18 | + | 1 | d | d | + | 1 | d | × | 3 | = | 0 |
| 2 | d | d | + | 15 | d | + | 18 | + | 1 | d | d | + | 3 | d | = | 0 |
| 2 | d | d | + | 18 | d | + | 18 | + | 1 | d | d | = | 0 |