66 5 | X | + | 100 | ( | 5 | − | X | ) | = | 65 | × | 5 |
| Left side of the equation = | 66 5 | X | + | 100 | × | 5 | − | 100 | X |
| = | 66 5 | X | + | 500 | − | 100 | X |
| = | - | 434 5 | X | + | 500 |
| - | 434 5 | X | + | 500 | = | 65 | × | 5 |
| Right side of the equation = | 325 |
| - | 434 5 | X | + | 500 | = | 325 |
| - | 434 5 | X | = | 325 | − | 500 |
| - | 434 5 | X | = | - | 175 |
| 175 | = | 434 5 | X |
434 5 | X | = | 175 |
| X | = | 175 | ÷ | 434 5 |
| = | 175 | × | 5 434 |
| = | 25 | × | 5 62 |
| X | = | 125 62 |
| X | = | 2.016129 |