| ( | 12801 | − | 6700 | x | ) | ( | 5557 | − | 18700 | x | ) | − | 5557 | × | 5557 | = | 0 |
| 方程左边 = | ( | 12801 | − | 6700 | x | ) | ( | 5557 | − | 18700 | x | ) | − | 30880249 |
| ( | 12801 | − | 6700 | x | ) | ( | 5557 | − | 18700 | x | ) | − | 30880249 | = | 0 |
| 方程左边 = | 12801 | ( | 5557 | − | 18700 | x | ) | − | 6700 | x | ( | 5557 | − | 18700 | x | ) | − | 30880249 |
| = | 12801 | × | 5557 | − | 12801 | × | 18700 | x | − | 6700 | x | ( | 5557 | − | 18700 | x | ) | − | 30880249 |
| = | 71135157 | − | 239378700 | x | − | 6700 | x | ( | 5557 | − | 18700 | x | ) | − | 30880249 |
| = | 40254908 | − | 239378700 | x | − | 6700 | x | ( | 5557 | − | 18700 | x | ) |
| = | 40254908 | − | 239378700 | x | − | 6700 | x | × | 5557 | + | 6700 | x | × | 18700 | x |
| = | 40254908 | − | 239378700 | x | − | 37231900 | x | + | 125290000 | x | x |
| = | 40254908 | − | 276610600 | x | + | 125290000 | x | x |
| 40254908 | − | 276610600 | x | + | 125290000 | x | x | = | 0 |