| 27 | ÷ | 189 | = | X | ÷ | ( | 1 | − | X | ) |
| Multiply both sides of the equation by: | ( | 1 | − | X | ) |
| 27 | ÷ | 189 | × | ( | 1 | − | X | ) | = | X |
| 27 | ÷ | 189 | × | 1 | − | 27 | ÷ | 189 | × | X | = | X |
1 7 | − | 1 7 | X | = | X |
| - | 1 7 | X | − | X | = | - | 1 7 |
| - | 8 7 | X | = | - | 1 7 |
1 7 | = | 8 7 | X |
8 7 | X | = | 1 7 |
| X | = | 1 7 | ÷ | 8 7 |
| = | 1 7 | × | 7 8 |
| = | 1 | × | 1 8 |
| X | = | 1 8 |
| X | = | 0.125 |