| ( | 10000 | − | X | ) | ÷ | X | = | - | 19 100 |
| Multiply both sides of the equation by: | X |
| ( | 10000 | − | X | ) | = | - | 19 100 | X |
| 10000 | − | X | = | - | 19 100 | X |
| - | X | + | 19 100 | X | = | - | 10000 |
| - | 81 100 | X | = | - | 10000 |
| 10000 | = | 81 100 | X |
81 100 | X | = | 10000 |
| X | = | 10000 | ÷ | 81 100 |
| = | 10000 | × | 100 81 |
| X | = | 1000000 81 |
| X | = | 12345.679012 |