| 400 | − | 100 | ÷ | 80 100 | × | X | − | 70 100 | X | = | 0 |
| Left side of the equation = | 400 | − | 125 | X | − | 70 100 | X |
| = | 400 | − | 1257 10 | X |
| 400 | − | 1257 10 | X | = | 0 |
| - | 1257 10 | X | = | 0 | − | 400 |
| - | 1257 10 | X | = | - | 400 |
| 400 | = | 1257 10 | X |
1257 10 | X | = | 400 |
| X | = | 400 | ÷ | 1257 10 |
| = | 400 | × | 10 1257 |
| X | = | 4000 1257 |
| X | = | 3.18218 |