| - | 141 20 | × | 1000000 | = | 69 5 | × | 1800 | x | ( | 1750 | − | x | ÷ | 2 | ) |
| 方程左边 = | - | 7050000 |
| - | 7050000 | = | 69 5 | × | 1800 | x | ( | 1750 | − | x | ÷ | 2 | ) |
| 方程右边 = | 24840 | x | ( | 1750 | − | x | ÷ | 2 | ) |
| - | 7050000 | = | 24840 | x | ( | 1750 | − | x | ÷ | 2 | ) |
| 方程右边 = | 24840 | x | × | 1750 | − | 24840 | x | x | ÷ | 2 |
| = | 43470000 | x | − | 12420 | x | x |
| - | 7050000 | = | 43470000 | x | − | 12420 | x | x |