| 30 | x | + | 50 | ( | 700 | − | x | ) | = | 29000 |
| Left side of the equation = | 30 | x | + | 50 | × | 700 | − | 50 | x |
| = | 30 | x | + | 35000 | − | 50 | x |
| = | - | 20 | x | + | 35000 |
| - | 20 | x | + | 35000 | = | 29000 |
| - | 20 | x | = | 29000 | − | 35000 |
| - | 20 | x | = | - | 6000 |
| 6000 | = | 20 | x |
| 20 | x | = | 6000 |
| x | = | 6000 | ÷ | 20 |
| = | 6000 | × | 1 20 |
| = | 300 | × | 1 |
| x | = | 300 |