| ( | 30 | X | − | 30 | X | X | X | X | X | ) | ÷ | ( | 1 | − | X | ) | = | 19284 125 |
| 方程两边同时乘以: | ( | 1 | − | X | ) |
| ( | 30 | X | − | 30 | X | X | X | X | X | ) | = | 19284 125 | ( | 1 | − | X | ) |
| 30 | X | − | 30 | X | X | X | X | X | = | 19284 125 | ( | 1 | − | X | ) |
| 30 | X | − | 30 | X | X | X | X | X | = | 19284 125 | × | 1 | − | 19284 125 | X |
| 30 | X | − | 30 | X | X | X | X | X | = | 19284 125 | − | 19284 125 | X |