231 10 | × | 1200 | x | ( | 300 | − | x | ÷ | 2 | ) | + | 360 | × | 4956 5 | ( | 300 | − | 50 | ) | = | 1270350 | × | 477117 1000 |
| 方程左边 = | 27720 | x | ( | 300 | − | x | ÷ | 2 | ) | + | 356832 | ( | 300 | − | 50 | ) |
| 27720 | x | ( | 300 | − | x | ÷ | 2 | ) | + | 356832 | ( | 300 | − | 50 | ) | = | 1270350 | × | 477117 1000 |
| 方程左边 = | 27720 | x | × | 300 | − | 27720 | x | x | ÷ | 2 | + | 356832 | ( | 300 | − | 50 | ) |
| = | 8316000 | x | − | 13860 | x | x | + | 356832 | ( | 300 | − | 50 | ) |
| = | 8316000 | x | − | 13860 | x | x | + | 356832 | × | 300 | − | 356832 | × | 50 |
| = | 8316000 | x | − | 13860 | x | x | + | 107049600 | − | 17841600 |
| = | 8316000 | x | − | 13860 | x | x | + | 89208000 |
| 8316000 | x | − | 13860 | x | x | + | 89208000 | = | 1270350 | × | 477117 1000 |