| ( | 610383 50 | − | X | ) | × | 30 | = | 12958 |
| 方程左边 = | 610383 50 | × | 30 | − | X | × | 30 |
| = | 1831149 5 | − | X | × | 30 |
1831149 5 | − | 30 | X | = | 12958 |
| - | 30 | X | = | 12958 | − | 1831149 5 |
| - | 30 | X | = | - | 1766359 5 |
1766359 5 | = | 30 | X |
| 30 | X | = | 1766359 5 |
| X | = | 1766359 5 | ÷ | 30 |
| = | 1766359 5 | × | 1 30 |
| X | = | 1766359 150 |
| X | = | 11775.726667 |