| 4700 | x | + | 7900 | ( | 6 | − | x | ) | = | 49000 |
| 方程左边 = | 4700 | x | + | 7900 | × | 6 | − | 7900 | x |
| = | 4700 | x | + | 47400 | − | 7900 | x |
| = | - | 3200 | x | + | 47400 |
| - | 3200 | x | + | 47400 | = | 49000 |
| - | 3200 | x | = | 49000 | − | 47400 |
| - | 3200 | x | = | 1600 |
| - | 1600 | = | 3200 | x |
| 3200 | x | = | - | 1600 |
| x | = | - | 1600 | ÷ | 3200 |
| = | - | 1600 | × | 1 3200 |
| = | - | 1 | × | 1 2 |
| x | = | - | 1 2 |
| x | = | - 0.5 |