| ( | 1000 | ( | 1 | + | 2 | a | ) | − | 2400 | a | − | 600 | ) | × | 50 | ( | 1 | + | 5 2 | a | ) | = | 20000 |
| 方程左边 = | 1000 | ( | 1 | + | 2 | a | ) | × | 50 | ( | 1 | + | 5 2 | a | ) | − | 2400 | a | × | 50 | ( | 1 | + | 5 2 | a | ) | − | 600 | × | 50 | ( | 1 | + | 5 2 | a | ) |
| = | 50000 | ( | 1 | + | 2 | a | ) | ( | 1 | + | 5 2 | a | ) | − | 120000 | a | ( | 1 | + | 5 2 | a | ) | − | 30000 | ( | 1 | + | 5 2 | a | ) |
| = | 50000 | × | 1 | ( | 1 | + | 5 2 | a | ) | + | 50000 | × | 2 | a | ( | 1 | + | 5 2 | a | ) | − | 120000 | a | ( | 1 | + | 5 2 | a | ) | − | 30000 | ( | 1 | + | 5 2 | a | ) |
| = | 50000 | ( | 1 | + | 5 2 | a | ) | + | 100000 | a | ( | 1 | + | 5 2 | a | ) | − | 120000 | a | ( | 1 | + | 5 2 | a | ) | − | 30000 | ( | 1 | + | 5 2 | a | ) |
| = | 50000 | × | 1 | + | 50000 | × | 5 2 | a | + | 100000 | a | ( | 1 | + | 5 2 | a | ) | − | 120000 | a | ( | 1 | + | 5 2 | a | ) | − | 30000 |
| = | 50000 | + | 125000 | a | + | 100000 | a | ( | 1 | + | 5 2 | a | ) | − | 120000 | a | ( | 1 | + | 5 2 | a | ) | − | 30000 | ( | 1 | + | 5 2 | a | ) |
| = | 50000 | + | 125000 | a | + | 100000 | a | × | 1 | + | 100000 | a | × | 5 2 | a | − | 120000 | a |
| = | 50000 | + | 125000 | a | + | 100000 | a | + | 250000 | a | a | − | 120000 | a | ( | 1 | + | 5 2 | a | ) | − | 30000 |
| = | 50000 | + | 225000 | a | + | 250000 | a | a | − | 120000 | a | ( | 1 | + | 5 2 | a | ) | − | 30000 | ( | 1 | + | 5 2 | a | ) |
| = | 50000 | + | 225000 | a | + | 250000 | a | a | − | 120000 | a | × | 1 | − | 120000 | a | × | 5 2 |
| = | 50000 | + | 225000 | a | + | 250000 | a | a | − | 120000 | a | − | 300000 | a | a | − | 30000 |
| = | 50000 | + | 105000 | a | + | 250000 | a | a | − | 300000 | a | a | − | 30000 | ( | 1 | + | 5 2 | a | ) |
| = | 50000 | + | 105000 | a | + | 250000 | a | a | − | 300000 | a | a | − | 30000 | × | 1 | − | 30000 |
| = | 50000 | + | 105000 | a | + | 250000 | a | a | − | 300000 | a | a | − | 30000 | − | 75000 | a |
| = | 20000 | + | 30000 | a | + | 250000 | a | a | − | 300000 | a | a |
| 20000 | + | 30000 | a | + | 250000 | a | a | − | 300000 | a | a | = | 20000 |
| a2= | 3 5 |