| 1600 | ( | 1 | + | x | ) | ( | 20 | ( | 1 | − | 1 5 | x | ) | − | 12 | × | 5 4 | ) | = | 8000 |
| 方程左边 = | 1600 | × | 1 | ( | 20 | ( | 1 | − | 1 5 | x | ) | − | 12 | × | 5 4 | ) | + | 1600 | x | ( | 20 | ( | 1 | − | 1 5 | x | ) | − | 12 | × | 5 4 | ) |
| = | 1600 | ( | 20 | ( | 1 | − | 1 5 | x | ) | − | 12 | × | 5 4 | ) | + | 1600 | x | ( | 20 | ( | 1 | − | 1 5 | x | ) | − | 12 | × | 5 4 | ) |
| = | 1600 | × | 20 | ( | 1 | − | 1 5 | x | ) | − | 1600 | × | 12 | × | 5 4 | + | 1600 | x | ( | 20 | ( | 1 | − | 1 5 | x | ) | − | 12 | × | 5 4 | ) |
| = | 32000 | ( | 1 | − | 1 5 | x | ) | − | 24000 | + | 1600 | x | ( | 20 | ( | 1 | − | 1 5 | x | ) | − | 12 | × | 5 4 | ) |
| = | 32000 | × | 1 | − | 32000 | × | 1 5 | x | − | 24000 | + | 1600 | x | ( | 20 | ( | 1 | − | 1 5 | x | ) | − | 12 | × | 5 4 | ) |
| = | 32000 | − | 6400 | x | − | 24000 | + | 1600 | x | ( | 20 | ( | 1 | − | 1 5 | x | ) | − | 12 | × | 5 4 | ) |
| = | 8000 | − | 6400 | x | + | 1600 | x | ( | 20 | ( | 1 | − | 1 5 | x | ) | − | 12 | × | 5 4 | ) |
| = | 8000 | − | 6400 | x | + | 1600 | x | × | 20 | ( | 1 | − | 1 5 | x | ) | − | 1600 | x | × | 12 | × | 5 4 |
| = | 8000 | − | 6400 | x | + | 32000 | x | ( | 1 | − | 1 5 | x | ) | − | 24000 | x |
| = | 8000 | − | 30400 | x | + | 32000 | x | ( | 1 | − | 1 5 | x | ) |
| = | 8000 | − | 30400 | x | + | 32000 | x | × | 1 | − | 32000 | x | × | 1 5 | x |
| = | 8000 | − | 30400 | x | + | 32000 | x | − | 6400 | x | x |
| = | 8000 | + | 1600 | x | − | 6400 | x | x |
| 8000 | + | 1600 | x | − | 6400 | x | x | = | 8000 |
| x2= | 1 4 |