| 3 | = | 100 | ( | X | − | 200 | ) | ÷ | ( | X | × | 950 | ÷ | 100 | ) |
| 方程两边同时乘以: | ( | X | × | 950 | ÷ | 100 | ) |
| 3 | ( | X | × | 950 | ÷ | 100 | ) | = | 100 | ( | X | − | 200 | ) |
| 3 | X | × | 950 | ÷ | 100 | = | 100 | ( | X | − | 200 | ) |
| 3 | X | × | 950 | ÷ | 100 | = | 100 | X | − | 100 | × | 200 |
57 2 | X | = | 100 | X | − | 20000 |
57 2 | X | − | 100 | X | = | - | 20000 |
| - | 143 2 | X | = | - | 20000 |
| 20000 | = | 143 2 | X |
143 2 | X | = | 20000 |
| X | = | 20000 | ÷ | 143 2 |
| = | 20000 | × | 2 143 |
| X | = | 40000 143 |
| X | = | 279.72028 |