| 2 | × | 280 | ÷ | x | + | 40 | = | 280 | − | 2 | × | 208 | ÷ | x |
| 方程两边同时乘以: | x |
| 2 | × | 280 | + | 40 | x | = | 280 | x | − | 2 | × | 208 | ÷ | 1 | × | 1 |
| 40 | x | − | 280 | x | = | - | 2 | × | 208 | ÷ | 1 | × | 1 | − | 2 | × | 280 |
| 40 | x | − | 280 | x | = | - | 416 | − | 560 |
| - | 240 | x | = | - | 416 | − | 560 |
| - | 240 | x | = | - | 976 |
| 976 | = | 240 | x |
| 240 | x | = | 976 |
| x | = | 976 | ÷ | 240 |
| = | 976 | × | 1 240 |
| = | 61 | × | 1 15 |
| x | = | 61 15 |
| x | = | 4.066667 |