| 23 | × | 100 | ÷ | X | ÷ | 21 20 | ÷ | 90 | × | 100 | = | 43 |
| Multiply both sides of the equation by: | X |
| 23 | × | 100 | ÷ | 21 20 | ÷ | 90 | × | 100 | = | 43 | X |
| - | 43 | X | = | - | 23 | × | 100 | ÷ | 21 20 | ÷ | 90 | × | 100 |
| - | 43 | X | = | - | 460000 189 |
460000 189 | = | 43 | X |
| 43 | X | = | 460000 189 |
| X | = | 460000 189 | ÷ | 43 |
| = | 460000 189 | × | 1 43 |
| X | = | 460000 8127 |
| X | = | 56.601452 |