| 1600 | ( | 1 | + | 2 5 | ) | − | 1600 | = | 2 | ( | 1 | + | 2 5 | ) | x |
| 方程左边 = | 1600 | × | 1 | + | 1600 | × | 2 5 | − | 1600 |
| = | 1600 | + | 640 | − | 1600 |
| = | 640 |
| 640 | = | 2 | ( | 1 | + | 2 5 | ) | x |
| 方程右边 = | 2 | × | 1 | x | + | 2 | × | 2 5 | x |
| = | 2 | x | + | 4 5 | x |
| = | 14 5 | x |
| 640 | = | 14 5 | x |
| - | 14 5 | x | = | - | 640 |
| 640 | = | 14 5 | x |
14 5 | x | = | 640 |
| x | = | 640 | ÷ | 14 5 |
| = | 640 | × | 5 14 |
| = | 320 | × | 5 7 |
| x | = | 1600 7 |
| x | = | 228.571429 |