11 20 | X | + | 3 5 | ( | 500 | − | X | ) | = | 581 2 |
| Left side of the equation = | 11 20 | X | + | 3 5 | × | 500 | − | 3 5 | X |
| = | 11 20 | X | + | 300 | − | 3 5 | X |
| = | - | 1 20 | X | + | 300 |
| - | 1 20 | X | + | 300 | = | 581 2 |
| - | 1 20 | X | = | 581 2 | − | 300 |
| - | 1 20 | X | = | - | 19 2 |
19 2 | = | 1 20 | X |
1 20 | X | = | 19 2 |
| X | = | 19 2 | ÷ | 1 20 |
| = | 19 2 | × | 20 |
| = | 19 | × | 10 |
| X | = | 190 |