| ( | 100 | − | a | − | 60 | ) | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | = | 3300 |
| 方程左边 = | 100 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | − | a | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | − | 60 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 100 | × | 80 | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | − | a | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | − | 60 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 8000 | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | − | a | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | − | 60 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 8000 | × | 125 | ( | 30 | + | 60 | × | a% | ) | − | a | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | − | 60 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 1000000 | ( | 30 | + | 60 | × | a% | ) | − | a | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | − | 60 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 1000000 | × | 30 | + | 1000000 | × | 60 | × | a% | − | a | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | − | 60 | ( | 80 | ) | ( | 125 | ) |
| = | 30000000 | + | 600000 | a | − | a | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | − | 60 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 30000000 | + | 600000 | a | − | a | × | 80 | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) | − | 60 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 30000000 | + | 600000 | a | − | a | × | 80 | × | 125 | ( | 30 | + | 60 | × | a% | ) | − | 60 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 30000000 | + | 600000 | a | − | a | × | 10000 | ( | 30 | + | 60 | × | a% | ) | − | 60 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 30000000 | + | 600000 | a | − | a | × | 10000 | × | 30 | − | a | × | 10000 | × | 60 | × | a% | − | 60 | ( | 80 | ) |
| = | 30000000 | + | 600000 | a | − | a | × | 300000 | − | a | × | 6000 | a | − | 60 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 30000000 | + | 300000 | a | − | a | × | 6000 | a | − | 60 | ( | 80 | ) | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 30000000 | + | 300000 | a | − | a | × | 6000 | a | − | 60 | × | 80 | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 30000000 | + | 300000 | a | − | a | × | 6000 | a | − | 4800 | ( | 125 | ) | ( | 30 | + | 60 | × | a% | ) |
| = | 30000000 | + | 300000 | a | − | a | × | 6000 | a | − | 4800 | × | 125 | ( | 30 | + | 60 | × | a% | ) |
| = | 30000000 | + | 300000 | a | − | a | × | 6000 | a | − | 600000 | ( | 30 | + | 60 | × | a% | ) |
| = | 30000000 | + | 300000 | a | − | a | × | 6000 | a | − | 600000 | × | 30 | − | 600000 | × | 60 | × | a% |
| = | 30000000 | + | 300000 | a | − | a | × | 6000 | a | − | 18000000 | − | 360000 | a |
| = | 12000000 | − | 60000 | a | − | a | × | 6000 | a |
| 12000000 | − | 60000 | a | − | a | × | 6000 | a | = | 3300 |