| 50000000 | = | 143 10 | × | 200 | x | ( | 360 | − | ( | x | ÷ | 2 | ) | ) |
| 方程右边 = | 2860 | x | ( | 360 | − | ( | x | ÷ | 2 | ) | ) |
| 50000000 | = | 2860 | x | ( | 360 | − | ( | x | ÷ | 2 | ) | ) |
| 方程右边 = | 2860 | x | × | 360 | − | 2860 | x | ( | x | ÷ | 2 | ) |
| = | 1029600 | x | − | 2860 | x | ( | x | ÷ | 2 | ) |
| = | 1029600 | x | − | 2860 | x | x | ÷ | 2 |
| = | 1029600 | x | − | 1430 | x | x |
| 50000000 | = | 1029600 | x | − | 1430 | x | x |