| ( | ( | x | − | 850 | ) | × | 75 100 | ) | ÷ | 7000 | = | ( | ( | x | − | 1200 | ) | × | 75 100 | ) | ÷ | 6000 |
| 方程左边 = | ( | x | − | 850 | ) | × | 75 100 | × | 1 7000 |
| = | ( | x | − | 850 | ) | × | 3 28000 |
| = | x | × | 3 28000 | − | 850 | × | 3 28000 |
| = | x | × | 3 28000 | − | 51 560 |
3 28000 | x | − | 51 560 | = | ( | ( | x | − | 1200 | ) | × | 75 100 | ) | ÷ | 6000 |
| 方程右边 = | ( | x | − | 1200 | ) | × | 75 100 | × | 1 6000 |
| = | ( | x | − | 1200 | ) | × | 1 8000 |
| = | x | × | 1 8000 | − | 1200 | × | 1 8000 |
| = | x | × | 1 8000 | − | 3 20 |
3 28000 | x | − | 51 560 | = | 1 8000 | x | − | 3 20 |
3 28000 | x | − | 1 8000 | x | = | - | 3 20 | + | 51 560 |
| - | 1 56000 | x | = | - | 3 20 | + | 51 560 |
| - | 1 56000 | x | = | - | 33 560 |
33 560 | = | 1 56000 | x |
1 56000 | x | = | 33 560 |
| x | = | 33 560 | ÷ | 1 56000 |
| = | 33 560 | × | 56000 |
| = | 33 | × | 100 |
| x | = | 3300 |