| ( | 45 | − | X | ) | × | 23 | ÷ | 15 | = | 57 | − | X |
| Left side of the equation = | ( | 45 | − | X | ) | × | 23 15 |
| ( | 45 | − | X | ) | × | 23 15 | = | 57 | − | X |
| Left side of the equation = | 45 | × | 23 15 | − | X | × | 23 15 |
| = | 69 | − | X | × | 23 15 |
| 69 | − | 23 15 | X | = | 57 | − | X |
| - | 23 15 | X | + | X | = | 57 | − | 69 |
| - | 8 15 | X | = | 57 | − | 69 |
| - | 8 15 | X | = | - | 12 |
| 12 | = | 8 15 | X |
8 15 | X | = | 12 |
| X | = | 12 | ÷ | 8 15 |
| = | 12 | × | 15 8 |
| = | 3 | × | 15 2 |
| X | = | 45 2 |
| X | = | 22.5 |