| X | − | ( | X | × | 1 10 | ) | − | ( | X | × | 1 5 | ) | − | 7 | = | 500 |
| Left side of the equation = | X | − | X | × | 1 10 | − | ( | X | × | 1 5 | ) | − | 7 |
| = | 9 10 | X | − | ( | X | × | 1 5 | ) | − | 7 |
| = | 9 10 | X | − | X | × | 1 5 | − | 7 |
| = | 7 10 | X | − | 7 |
7 10 | X | − | 7 | = | 500 |
7 10 | X | = | 500 | + | 7 |
7 10 | X | = | 507 |
| X | = | 507 | ÷ | 7 10 |
| = | 507 | × | 10 7 |
| X | = | 5070 7 |
| X | = | 724.285714 |