| 2000 | ( | x | − | 100 | ) | = | ( | x | − | 1000 | ) | ( | 3 | x | + | 200 | ) |
| 方程左边 = | 2000 | x | − | 2000 | × | 100 |
| = | 2000 | x | − | 200000 |
| 2000 | x | − | 200000 | = | ( | x | − | 1000 | ) | ( | 3 | x | + | 200 | ) |
| 方程右边 = | x | ( | 3 | x | + | 200 | ) | − | 1000 | ( | 3 | x | + | 200 | ) |
| = | x | × | 3 | x | + | x | × | 200 | − | 1000 | ( | 3 | x | + | 200 | ) |
| = | x | × | 3 | x | + | 200 | x | − | 1000 | × | 3 | x | − | 1000 | × | 200 |
| = | x | × | 3 | x | + | 200 | x | − | 3000 | x | − | 200000 |
| = | x | × | 3 | x | − | 2800 | x | − | 200000 |
| 2000 | x | − | 200000 | = | x | × | 3 | x | − | 2800 | x | − | 200000 |