| 150 | ( | 30 | ( | 1 | + | m% | ) | − | 20 | ) | + | 100 | ( | 35 | ( | 1 | − | m% | ) | − | ( | 25 | − | 2 | ) | ) | = | 2500 | + | 270 |
| 方程左边 = | 150 | × | 30 | ( | 1 | + | m% | ) | − | 150 | × | 20 | + | 100 | ( | 35 | ( | 1 | − | m% | ) | − | ( | 25 | − | 2 | ) | ) |
| = | 4500 | ( | 1 | + | m% | ) | − | 3000 | + | 100 | ( | 35 | ( | 1 | − | m% | ) | − | ( | 25 | − | 2 | ) | ) |
| = | 4500 | × | 1 | + | 4500 | × | m% | − | 3000 | + | 100 | ( | 35 | ( | 1 | − | m% | ) | − | ( | 25 | − | 2 | ) | ) |
| = | 4500 | + | 45 | m | − | 3000 | + | 100 | ( | 35 | ( | 1 | − | m% | ) | − | ( | 25 | − | 2 | ) | ) |
| = | 1500 | + | 45 | m | + | 100 | ( | 35 | ( | 1 | − | m% | ) | − | ( | 25 | − | 2 | ) | ) |
| = | 1500 | + | 45 | m | + | 100 | × | 35 | ( | 1 | − | m% | ) | − | 100 | ( | 25 | − | 2 | ) |
| = | 1500 | + | 45 | m | + | 3500 | ( | 1 | − | m% | ) | − | 100 | ( | 25 | − | 2 | ) |
| = | 1500 | + | 45 | m | + | 3500 | × | 1 | − | 3500 | × | m% | − | 100 | ( | 25 | − | 2 | ) |
| = | 1500 | + | 45 | m | + | 3500 | − | 35 | m | − | 100 | ( | 25 | − | 2 | ) |
| = | 5000 | + | 10 | m | − | 100 | ( | 25 | − | 2 | ) |
| = | 5000 | + | 10 | m | − | 100 | × | 25 | + | 100 | × | 2 |
| = | 5000 | + | 10 | m | − | 2500 | + | 200 |
| = | 2700 | + | 10 | m |
| 2700 | + | 10 | m | = | 2500 | + | 270 |
| 方程右边 = | 2770 |
| 2700 | + | 10 | m | = | 2770 |
| 10 | m | = | 2770 | − | 2700 |
| 10 | m | = | 70 |
| m | = | 70 | ÷ | 10 |
| = | 70 | × | 1 10 |
| = | 7 | × | 1 |
| m | = | 7 |