| 26 | × | 100 | ÷ | X | ÷ | 21 20 | ÷ | 123 | × | 100 | = | 30 |
| Multiply both sides of the equation by: | X |
| 26 | × | 100 | ÷ | 21 20 | ÷ | 123 | × | 100 | = | 30 | X |
| - | 30 | X | = | - | 26 | × | 100 | ÷ | 21 20 | ÷ | 123 | × | 100 |
| - | 30 | X | = | - | 5200000 2583 |
5200000 2583 | = | 30 | X |
| 30 | X | = | 5200000 2583 |
| X | = | 5200000 2583 | ÷ | 30 |
| = | 5200000 2583 | × | 1 30 |
| = | 520000 2583 | × | 1 3 |
| X | = | 520000 7749 |
| X | = | 67.105433 |