| ( | X | − | 10 100 | ) | ÷ | ( | 15 100 | − | X | ) | = | 200 | ÷ | 100 |
| 方程两边同时乘以: | ( | 15 100 | − | X | ) |
| ( | X | − | 10 100 | ) | = | 200 | ÷ | 100 | × | ( | 15 100 | − | X | ) |
| X | − | 10 100 | = | 200 | ÷ | 100 | × | ( | 15 100 | − | X | ) |
| X | − | 10 100 | = | 200 | ÷ | 100 | × | 15 100 | − | 200 | ÷ | 100 | × | X |
| X | − | 10 100 | = | 3 10 | − | 2 | X |
| X | + | 2 | X | = | 3 10 | + | 10 100 |
| 3 | X | = | 3 10 | + | 10 100 |
| 3 | X | = | 2 5 |
| X | = | 2 5 | ÷ | 3 |
| = | 2 5 | × | 1 3 |
| X | = | 2 15 |
| X | = | 0.133333 |