6 5 | X | − | 15 | − | X | = | ( | 20 100 | − | 10 100 | ) | X |
| Left side of the equation = | 1 5 | X | − | 15 |
1 5 | X | − | 15 | = | ( | 20 100 | − | 10 100 | ) | X |
| Right side of the equation = | 20 100 | X | − | 10 100 | X |
| = | 1 10 | X |
1 5 | X | − | 15 | = | 1 10 | X |
1 5 | X | − | 1 10 | X | = | 15 |
1 10 | X | = | 15 |
| X | = | 15 | ÷ | 1 10 |
| = | 15 | × | 10 |
| X | = | 150 |