| ( | 618 | − | 2 | x | ) | ( | x | − | 259 | ) | = | 12000 |
| 方程左边 = | 618 | ( | x | − | 259 | ) | − | 2 | x | ( | x | − | 259 | ) |
| = | 618 | x | − | 618 | × | 259 | − | 2 | x | ( | x | − | 259 | ) |
| = | 618 | x | − | 160062 | − | 2 | x | ( | x | − | 259 | ) |
| = | 618 | x | − | 160062 | − | 2 | x | x | + | 2 | x | × | 259 |
| = | 618 | x | − | 160062 | − | 2 | x | x | + | 518 | x |
| = | 1136 | x | − | 160062 | − | 2 | x | x |
| 1136 | x | − | 160062 | − | 2 | x | x | = | 12000 |