| 50 | ( | 1 | − | m% | ) | × | 100 | ( | 1 | + | 60 100 | ) | + | 70 | ( | 1 | − | 2 | ÷ | 3 | × | m% | ) | × | 50 | ( | 1 | + | 40 100 | ) | = | 9520 |
| 方程左边 = | 5000 | ( | 1 | − | m% | ) | ( | 1 | + | 60 100 | ) | + | 3500 | ( | 1 | − | 2 | ÷ | 3 | × | m% | ) | ( | 1 | + | 40 100 | ) |
| 5000 | ( | 1 | − | m% | ) | ( | 1 | + | 60 100 | ) | + | 3500 | ( | 1 | − | 2 | ÷ | 3 | × | m% | ) | ( | 1 | + | 40 100 | ) | = | 9520 |
| 方程左边 = | 5000 | × | 1 | ( | 1 | + | 60 100 | ) | − | 5000 | × | m% | ( | 1 | + | 60 100 | ) | + | 3500 | ( | 1 | − | 2 | ÷ | 3 | × | m% | ) | ( | 1 | + | 40 100 | ) |
| = | 5000 | ( | 1 | + | 60 100 | ) | − | 50 | m | ( | 1 | + | 60 100 | ) | + | 3500 | ( | 1 | − | 2 | ÷ | 3 | × | m% | ) | ( | 1 | + | 40 100 | ) |
| = | 5000 | × | 1 | + | 5000 | × | 60 100 | − | 50 | m | ( | 1 | + | 60 100 | ) | + | 3500 | ( | 1 | − | 2 | ÷ | 3 | × | m% | ) | ( | 1 | + | 40 100 | ) |
| = | 5000 | + | 3000 | − | 50 | m | ( | 1 | + | 60 100 | ) | + | 3500 | ( | 1 | − | 2 | ÷ | 3 | × | m% | ) | ( | 1 | + | 40 100 | ) |
| = | 8000 | − | 50 | m | ( | 1 | + | 60 100 | ) | + | 3500 | ( | 1 | − | 2 | ÷ | 3 | × | m% | ) | ( | 1 | + | 40 100 | ) |
| = | 8000 | − | 50 | m | × | 1 | − | 50 | m | × | 60 100 | + | 3500 | ( | 1 | − | 2 | ÷ | 3 | × | m% | ) | ( | 1 | + | 40 100 | ) |
| = | 8000 | − | 50 | m | − | 30 | m | + | 3500 | ( | 1 | − | 2 | ÷ | 3 | × | m% | ) | ( | 1 | + | 40 100 | ) |
| = | 8000 | − | 80 | m | + | 3500 | ( | 1 | − | 2 | ÷ | 3 | × | m% | ) | ( | 1 | + | 40 100 | ) |
| = | 8000 | − | 80 | m | + | 3500 | × | 1 | ( | 1 | + | 40 100 | ) | − | 3500 | × | 2 | ÷ | 3 | × | m% | ( | 1 | + | 40 100 | ) |
| = | 8000 | − | 80 | m | + | 3500 | ( | 1 | + | 40 100 | ) | − | 70 3 | m | ( | 1 | + | 40 100 | ) |
| = | 8000 | − | 80 | m | + | 3500 | × | 1 | + | 3500 | × | 40 100 | − | 70 3 | m | ( | 1 | + | 40 100 | ) |
| = | 8000 | − | 80 | m | + | 3500 | + | 1400 | − | 70 3 | m | ( | 1 | + | 40 100 | ) |
| = | 12900 | − | 80 | m | − | 70 3 | m | ( | 1 | + | 40 100 | ) |
| = | 12900 | − | 80 | m | − | 70 3 | m | × | 1 | − | 70 3 | m | × | 40 100 |
| = | 12900 | − | 80 | m | − | 70 3 | m | − | 28 3 | m |
| = | 12900 | − | 338 3 | m |
| 12900 | − | 338 3 | m | = | 9520 |
| - | 338 3 | m | = | 9520 | − | 12900 |
| - | 338 3 | m | = | - | 3380 |
| 3380 | = | 338 3 | m |
338 3 | m | = | 3380 |
| m | = | 3380 | ÷ | 338 3 |
| = | 3380 | × | 3 338 |
| = | 10 | × | 3 |
| m | = | 30 |