| ( | x | − | 5 | ) | ( | 1213 2000 | − | 9 500 | x | ) | = | ( | 10 | − | x | ) | ( | 71 5000 | x | − | 769 2000 | ) |
| 方程左边 = | x | ( | 1213 2000 | − | 9 500 | x | ) | − | 5 | ( | 1213 2000 | − | 9 500 | x | ) |
| = | x | × | 1213 2000 | − | x | × | 9 500 | x | − | 5 | ( | 1213 2000 | − | 9 500 | x | ) |
| = | 1213 2000 | x | − | x | × | 9 500 | x | − | 5 | × | 1213 2000 | + | 5 | × | 9 500 | x |
| = | 1213 2000 | x | − | x | × | 9 500 | x | − | 1213 400 | + | 9 100 | x |
| = | 1393 2000 | x | − | x | × | 9 500 | x | − | 1213 400 |
1393 2000 | x | − | x | × | 9 500 | x | − | 1213 400 | = | ( | 10 | − | x | ) | ( | 71 5000 | x | − | 769 2000 | ) |
| 方程右边 = | 10 | ( | 71 5000 | x | − | 769 2000 | ) | − | x | ( | 71 5000 | x | − | 769 2000 | ) |
| = | 10 | × | 71 5000 | x | − | 10 | × | 769 2000 | − | x | ( | 71 5000 | x | − | 769 2000 | ) |
| = | 71 500 | x | − | 769 200 | − | x | ( | 71 5000 | x | − | 769 2000 | ) |
| = | 71 500 | x | − | 769 200 | − | x | × | 71 5000 | x | + | x | × | 769 2000 |
| = | 1053 2000 | x | − | 769 200 | − | x | × | 71 5000 | x |
1393 2000 | x | − | x | × | 9 500 | x | − | 1213 400 | = | 1053 2000 | x | − | 769 200 | − | x | × | 71 5000 | x |