| 32 | × | 20 | − | 20 | × | 20 | × | 157 50 | − | ( | 20 | − | x | ) | ( | 20 | − | x | ) | × | 157 50 | = | 540 |
| 方程左边 = | 640 | − | 1256 | − | ( | 20 | − | x | ) | ( | 20 | − | x | ) | × | 157 50 |
| = | - | 616 | − | ( | 20 | − | x | ) | ( | 20 | − | x | ) | × | 157 50 |
| - | 616 | − | ( | 20 | − | x | ) | ( | 20 | − | x | ) | × | 157 50 | = | 540 |
| 方程左边 = | - | 616 | − | 20 | ( | 20 | − | x | ) | × | 157 50 | + | x | ( | 20 | − | x | ) | × | 157 50 |
| = | - | 616 | − | 314 5 | ( | 20 | − | x | ) | + | x | ( | 20 | − | x | ) | × | 157 50 |
| = | - | 616 | − | 314 5 | × | 20 | + | 314 5 | x | + | x | ( | 20 | − | x | ) | × | 157 50 |
| = | - | 616 | − | 1256 | + | 314 5 | x | + | x | ( | 20 | − | x | ) | × | 157 50 |
| = | - | 1872 | + | 314 5 | x | + | x | ( | 20 | − | x | ) | × | 157 50 |
| = | - | 1872 | + | 314 5 | x | + | x | × | 20 | × | 157 50 | − | x | x | × | 157 50 |
| = | - | 1872 | + | 314 5 | x | + | x | × | 314 5 | − | x | x | × | 157 50 |
| = | - | 1872 | + | 628 5 | x | − | x | x | × | 157 50 |
| - | 1872 | + | 628 5 | x | − | x | x | × | 157 50 | = | 540 |