| 681506 | − | 30000 | x | − | 36000 | x | ÷ | 3 | − | 180000 | = | 0 |
| 方程左边 = | 681506 | − | 30000 | x | − | 12000 | x | − | 180000 |
| = | 501506 | − | 42000 | x |
| 501506 | − | 42000 | x | = | 0 |
| - | 42000 | x | = | 0 | − | 501506 |
| - | 42000 | x | = | - | 501506 |
| 501506 | = | 42000 | x |
| 42000 | x | = | 501506 |
| x | = | 501506 | ÷ | 42000 |
| = | 501506 | × | 1 42000 |
| = | 250753 | × | 1 21000 |
| x | = | 250753 21000 |
| x | = | 11.940619 |