| ( | 115 2 | − | X | ) | ÷ | 115 2 | = | 25 400 |
| Left side of the equation = | 115 2 | × | 2 115 | − | X | × | 2 115 |
| = | 1 | − | X | × | 2 115 |
| 1 | − | 2 115 | X | = | 25 400 |
| - | 2 115 | X | = | 25 400 | − | 1 |
| - | 2 115 | X | = | - | 15 16 |
15 16 | = | 2 115 | X |
2 115 | X | = | 15 16 |
| X | = | 15 16 | ÷ | 2 115 |
| = | 15 16 | × | 115 2 |
| X | = | 1725 32 |
| X | = | 53.90625 |