| ( | x | − | 5 | ) | ( | 747 1000 | − | 3 200 | x | ) | = | ( | 10 | − | x | ) | ( | 71 1000 | x | − | 19 500 | ) |
| 方程左边 = | x | ( | 747 1000 | − | 3 200 | x | ) | − | 5 | ( | 747 1000 | − | 3 200 | x | ) |
| = | x | × | 747 1000 | − | x | × | 3 200 | x | − | 5 | ( | 747 1000 | − | 3 200 | x | ) |
| = | 747 1000 | x | − | x | × | 3 200 | x | − | 5 | × | 747 1000 | + | 5 | × | 3 200 | x |
| = | 747 1000 | x | − | x | × | 3 200 | x | − | 747 200 | + | 3 40 | x |
| = | 411 500 | x | − | x | × | 3 200 | x | − | 747 200 |
411 500 | x | − | x | × | 3 200 | x | − | 747 200 | = | ( | 10 | − | x | ) | ( | 71 1000 | x | − | 19 500 | ) |
| 方程右边 = | 10 | ( | 71 1000 | x | − | 19 500 | ) | − | x | ( | 71 1000 | x | − | 19 500 | ) |
| = | 10 | × | 71 1000 | x | − | 10 | × | 19 500 | − | x | ( | 71 1000 | x | − | 19 500 | ) |
| = | 71 100 | x | − | 19 50 | − | x | ( | 71 1000 | x | − | 19 500 | ) |
| = | 71 100 | x | − | 19 50 | − | x | × | 71 1000 | x | + | x | × | 19 500 |
| = | 187 250 | x | − | 19 50 | − | x | × | 71 1000 | x |
411 500 | x | − | x | × | 3 200 | x | − | 747 200 | = | 187 250 | x | − | 19 50 | − | x | × | 71 1000 | x |