| r | r | r | r | ÷ | ( | ( | r | − | 3000 | ) | ( | r | − | 3000 | ) | ) | = | 16776404030 |
| 方程两边同时乘以: | ( | ( | r | − | 3000 | ) | ( | r | − | 3000 | ) | ) |
| r | r | r | r | = | 16776404030 | ( | ( | r | − | 3000 | ) | ( | r | − | 3000 | ) | ) |
| r | r | r | r | = | 16776404030 | ( | r | − | 3000 | ) | ( | r | − | 3000 | ) |
| r | r | r | r | = | 16776404030 | r | ( | r | − | 3000 | ) | − | 16776404030 | × | 3000 | ( | r | − | 3000 | ) |