| 120000 | + | 210 | x | + | 10000 | = | 3000 | x |
| Left side of the equation = | 130000 | + | 210 | x |
| 130000 | + | 210 | x | = | 3000 | x |
| 210 | x | − | 3000 | x | = | - | 130000 |
| - | 2790 | x | = | - | 130000 |
| 130000 | = | 2790 | x |
| 2790 | x | = | 130000 |
| x | = | 130000 | ÷ | 2790 |
| = | 130000 | × | 1 2790 |
| = | 13000 | × | 1 279 |
| x | = | 13000 279 |
| x | = | 46.594982 |