| 57 | × | 100 | ÷ | X | ÷ | 21 20 | ÷ | 90 | × | 100 | = | 101 |
| Multiply both sides of the equation by: | X |
| 57 | × | 100 | ÷ | 21 20 | ÷ | 90 | × | 100 | = | 101 | X |
| - | 101 | X | = | - | 57 | × | 100 | ÷ | 21 20 | ÷ | 90 | × | 100 |
| - | 101 | X | = | - | 380000 63 |
380000 63 | = | 101 | X |
| 101 | X | = | 380000 63 |
| X | = | 380000 63 | ÷ | 101 |
| = | 380000 63 | × | 1 101 |
| X | = | 380000 6363 |
| X | = | 59.720258 |