| ( | 7700 | − | x | ) | ÷ | x | = | 13 100 |
| Multiply both sides of the equation by: | x |
| ( | 7700 | − | x | ) | = | 13 100 | x |
| 7700 | − | x | = | 13 100 | x |
| - | x | − | 13 100 | x | = | - | 7700 |
| - | 113 100 | x | = | - | 7700 |
| 7700 | = | 113 100 | x |
113 100 | x | = | 7700 |
| x | = | 7700 | ÷ | 113 100 |
| = | 7700 | × | 100 113 |
| x | = | 770000 113 |
| x | = | 6814.159292 |