| a | ÷ | ( | 1 | + | a | ) | ÷ | ( | 1 | + | a | ÷ | ( | 1 | + | a | ) | ) | ÷ | ( | 1 | + | a | ÷ | ( | 1 | + | a | ) | ÷ | ( | 1 | + | a | ÷ | ( | 1 | + | a | ) | ) | ) | = | 0 |
| 方程两边同时乘以: | ( | 1 | + | a | ) |
| a | ÷ | ( | 1 | + | a | ÷ | ( | 1 | + | a | ) | ) | ÷ | ( | 1 | + | a | ÷ | ( | 1 | + | a | ) | ÷ | ( | 1 | + | a | ÷ | ( | 1 | + | a | ) | ) | ) | = | 0 |
| 方程两边同时乘以: | ( | 1 | + | a | ÷ | ( | 1 | + | a | ) | ) |
| a | ÷ | ( | 1 | + | a | ÷ | ( | 1 | + | a | ) | ÷ | ( | 1 | + | a | ÷ | ( | 1 | + | a | ) | ) | ) | = | 0 |
| 方程两边同时乘以: | ( | 1 | + | a | ÷ | ( | 1 | + | a | ) | ÷ | ( | 1 | + | a | ÷ | ( | 1 | + | a | ) | ) | ) |
| a | = | 0 |