| 120000 | + | 210 | x | + | 10000 | + | 8000 | = | 3000 | x |
| Left side of the equation = | 138000 | + | 210 | x |
| 138000 | + | 210 | x | = | 3000 | x |
| 210 | x | − | 3000 | x | = | - | 138000 |
| - | 2790 | x | = | - | 138000 |
| 138000 | = | 2790 | x |
| 2790 | x | = | 138000 |
| x | = | 138000 | ÷ | 2790 |
| = | 138000 | × | 1 2790 |
| = | 4600 | × | 1 93 |
| x | = | 4600 93 |
| x | = | 49.462366 |