| 400 | ÷ | ( | X | + | 400 | ) | = | 49 100 |
| 方程两边同时乘以: | ( | X | + | 400 | ) |
| 400 | = | 49 100 | ( | X | + | 400 | ) |
| 400 | = | 49 100 | X | + | 49 100 | × | 400 |
| 400 | = | 49 100 | X | + | 196 |
| - | 49 100 | X | = | 196 | − | 400 |
| - | 49 100 | X | = | - | 204 |
| 204 | = | 49 100 | X |
49 100 | X | = | 204 |
| X | = | 204 | ÷ | 49 100 |
| = | 204 | × | 100 49 |
| X | = | 20400 49 |
| X | = | 416.326531 |