| 15 | = | 100 | ( | X | − | 60 | ) | ÷ | ( | X | × | 30 | ÷ | 100 | ) |
| Multiply both sides of the equation by: | ( | X | × | 30 | ÷ | 100 | ) |
| 15 | ( | X | × | 30 | ÷ | 100 | ) | = | 100 | ( | X | − | 60 | ) |
| 15 | X | × | 30 | ÷ | 100 | = | 100 | ( | X | − | 60 | ) |
| 15 | X | × | 30 | ÷ | 100 | = | 100 | X | − | 100 | × | 60 |
9 2 | X | = | 100 | X | − | 6000 |
9 2 | X | − | 100 | X | = | - | 6000 |
| - | 191 2 | X | = | - | 6000 |
| 6000 | = | 191 2 | X |
191 2 | X | = | 6000 |
| X | = | 6000 | ÷ | 191 2 |
| = | 6000 | × | 2 191 |
| X | = | 12000 191 |
| X | = | 62.827225 |