| 6230 | x | + | 6720 | ( | 12 | − | x | ) | = | 76800 |
| Left side of the equation = | 6230 | x | + | 6720 | × | 12 | − | 6720 | x |
| = | 6230 | x | + | 80640 | − | 6720 | x |
| = | - | 490 | x | + | 80640 |
| - | 490 | x | + | 80640 | = | 76800 |
| - | 490 | x | = | 76800 | − | 80640 |
| - | 490 | x | = | - | 3840 |
| 3840 | = | 490 | x |
| 490 | x | = | 3840 |
| x | = | 3840 | ÷ | 490 |
| = | 3840 | × | 1 490 |
| = | 384 | × | 1 49 |
| x | = | 384 49 |
| x | = | 7.836735 |