| 4500 | = | ( | X | − | 25 | ) | × | 400 | + | 5000 |
| Right side of the equation = | X | × | 400 | − | 25 | × | 400 | + | 5000 |
| = | X | × | 400 | − | 10000 | + | 5000 |
| = | 400 | X | − | 5000 |
| 4500 | = | 400 | X | − | 5000 |
| - | 400 | X | = | - | 5000 | − | 4500 |
| - | 400 | X | = | - | 9500 |
| 9500 | = | 400 | X |
| 400 | X | = | 9500 |
| X | = | 9500 | ÷ | 400 |
| = | 9500 | × | 1 400 |
| = | 95 | × | 1 4 |
| X | = | 95 4 |
| X | = | 23.75 |