| ( | X | + | 15 | ) | ÷ | ( | X | − | 10 | ) | = | 6 |
| Multiply both sides of the equation by: | ( | X | − | 10 | ) |
| ( | X | + | 15 | ) | = | 6 | ( | X | − | 10 | ) |
| X | + | 15 | = | 6 | ( | X | − | 10 | ) |
| X | + | 15 | = | 6 | X | − | 6 | × | 10 |
| X | + | 15 | = | 6 | X | − | 60 |
| X | − | 6 | X | = | - | 60 | − | 15 |
| - | 5 | X | = | - | 60 | − | 15 |
| - | 5 | X | = | - | 75 |
| 75 | = | 5 | X |
| 5 | X | = | 75 |
| X | = | 75 | ÷ | 5 |
| = | 75 | × | 1 5 |
| = | 15 | × | 1 |
| X | = | 15 |