| X | ÷ | 87 | − | ( | 80 | − | X | ) | ÷ | 500 | − | 1 50 | = | 131 1000 |
| 方程左边 = | 1 87 | X | − | 80 | × | 1 500 | + | X | × | 1 500 | − | 1 50 |
| = | 1 87 | X | − | 4 25 | + | X | × | 1 500 | − | 1 50 |
| = | 587 43500 | X | − | 9 50 |
587 43500 | X | − | 9 50 | = | 131 1000 |
587 43500 | X | = | 131 1000 | + | 9 50 |
587 43500 | X | = | 311 1000 |
| X | = | 311 1000 | ÷ | 587 43500 |
| = | 311 1000 | × | 43500 587 |
| = | 311 2 | × | 87 587 |
| X | = | 27057 1174 |
| X | = | 23.046848 |