| ( | 1 | ÷ | ( | n | − | 3 | ) | + | 1 | ÷ | ( | n | + | 6 | ) | ) | × | 3 | + | 1 | ÷ | ( | n | + | 6 | ) | × | ( | n | − | 3 | ) | = | 0 |
| 方程两边同时乘以: | ( | n | + | 6 | ) |
| ( | 1 | ÷ | ( | n | − | 3 | ) | + | 1 | ÷ | ( | n | + | 6 | ) | ) | × | 3 | ( | n | + | 6 | ) | + | 1 | ( | n | − | 3 | ) | = | 0 |
| 1 | ÷ | ( | n | − | 3 | ) | × | 3 | ( | n | + | 6 | ) | + | 1 | ÷ | ( | n | + | 6 | ) | × | 3 | ( | n | + | 6 | ) | + | 1 | ( | n | − | 3 | ) | = | 0 |
| 3 | ÷ | ( | n | − | 3 | ) | × | ( | n | + | 6 | ) | + | 3 | ÷ | ( | n | + | 6 | ) | × | ( | n | + | 6 | ) | + | 1 | ( | n | − | 3 | ) | = | 0 |
| 方程两边同时乘以: | ( | n | − | 3 | ) |
| 3 | ( | n | + | 6 | ) | + | 3 | ÷ | ( | n | + | 6 | ) | × | ( | n | + | 6 | ) | ( | n | − | 3 | ) | + | 1 | ( | n | − | 3 | ) | ( | n | − | 3 | ) | = | 0 |
| 3 | n | + | 3 | × | 6 | + | 3 | ÷ | ( | n | + | 6 | ) | × | ( | n | + | 6 | ) | ( | n | − | 3 | ) | + | 1 | ( | n | − | 3 | ) | ( | n | − | 3 | ) | = | 0 |
| 3 | n | + | 18 | + | 3 | ÷ | ( | n | + | 6 | ) | × | ( | n | + | 6 | ) | ( | n | − | 3 | ) | + | 1 | ( | n | − | 3 | ) | ( | n | − | 3 | ) | = | 0 |
| 方程两边同时乘以: | ( | n | + | 6 | ) |
| 3 | n | ( | n | + | 6 | ) | + | 18 | ( | n | + | 6 | ) | + | 3 | ( | n | + | 6 | ) | ( | n | − | 3 | ) | + | 1 | ( | n | − | 3 | ) | ( | n | − | 3 | ) | ( | n | + | 6 | ) | = | 0 |
| 3 | n | n | + | 3 | n | × | 6 | + | 18 | ( | n | + | 6 | ) | + | 3 | ( | n | + | 6 | ) | ( | n | − | 3 | ) | + | 1 | = | 0 |
| 3 | n | n | + | 18 | n | + | 18 | ( | n | + | 6 | ) | + | 3 | ( | n | + | 6 | ) | ( | n | − | 3 | ) | + | 1 | ( | n | − | 3 | ) | = | 0 |
| 3 | n | n | + | 18 | n | + | 18 | n | + | 18 | × | 6 | + | 3 | ( | n | + | 6 | ) | ( | n | − | 3 | ) | = | 0 |
| 3 | n | n | + | 18 | n | + | 18 | n | + | 108 | + | 3 | ( | n | + | 6 | ) | ( | n | − | 3 | ) | + | 1 | = | 0 |
| 3 | n | n | + | 36 | n | + | 108 | + | 3 | ( | n | + | 6 | ) | ( | n | − | 3 | ) | + | 1 | ( | n | − | 3 | ) | ( | n | − | 3 | ) | = | 0 |
| 3 | n | n | + | 36 | n | + | 108 | + | 3 | n | ( | n | − | 3 | ) | + | 3 | × | 6 | ( | n | − | 3 | ) | = | 0 |
| 3 | n | n | + | 36 | n | + | 108 | + | 3 | n | ( | n | − | 3 | ) | + | 18 | ( | n | − | 3 | ) | + | 1 | = | 0 |
| 3 | n | n | + | 36 | n | + | 108 | + | 3 | n | n | − | 3 | n | × | 3 | = | 0 |
| 3 | n | n | + | 36 | n | + | 108 | + | 3 | n | n | − | 9 | n | + | 18 | = | 0 |
| 3 | n | n | + | 27 | n | + | 108 | + | 3 | n | n | + | 18 | ( | n | − | 3 | ) | + | 1 | = | 0 |
| 3 | n | n | + | 27 | n | + | 108 | + | 3 | n | n | + | 18 | n | − | 18 | = | 0 |
| 3 | n | n | + | 27 | n | + | 108 | + | 3 | n | n | + | 18 | n | − | 54 | = | 0 |
| 3 | n | n | + | 45 | n | + | 54 | + | 3 | n | n | + | 1 | ( | n | − | 3 | ) | ( | n | − | 3 | ) | = | 0 |
| 3 | n | n | + | 45 | n | + | 54 | + | 3 | n | n | + | 1 | n | ( | n | − | 3 | ) | = | 0 |
| 3 | n | n | + | 45 | n | + | 54 | + | 3 | n | n | + | 1 | n | ( | n | − | 3 | ) | = | 0 |
| 3 | n | n | + | 45 | n | + | 54 | + | 3 | n | n | + | 1 | n | n | = | 0 |