| 69 | X | ÷ | ( | 100 | + | X | ) | = | 61 25 |
| Multiply both sides of the equation by: | ( | 100 | + | X | ) |
| 69 | X | = | 61 25 | ( | 100 | + | X | ) |
| 69 | X | = | 61 25 | × | 100 | + | 61 25 | X |
| 69 | X | = | 244 | + | 61 25 | X |
| 69 | X | − | 61 25 | X | = | 244 |
1664 25 | X | = | 244 |
| X | = | 244 | ÷ | 1664 25 |
| = | 244 | × | 25 1664 |
| = | 61 | × | 25 416 |
| X | = | 1525 416 |
| X | = | 3.665865 |