| 6 | x | + | ( | 25 | − | x | ) | ( | 12 | − | 8 | ) | = | 330 |
| Left side of the equation = | 6 | x | + | 25 | ( | 12 | − | 8 | ) | − | x | ( | 12 | − | 8 | ) |
| = | 6 | x | + | 25 | × | 12 | − | 25 | × | 8 | − | x | ( | 12 | − | 8 | ) |
| = | 6 | x | + | 300 | − | 200 | − | x | ( | 12 | − | 8 | ) |
| = | 6 | x | + | 100 | − | x | ( | 12 | − | 8 | ) |
| = | 6 | x | + | 100 | − | x | × | 12 | + | x | × | 8 |
| = | 2 | x | + | 100 |
| 2 | x | + | 100 | = | 330 |
| 2 | x | = | 330 | − | 100 |
| 2 | x | = | 230 |
| x | = | 230 | ÷ | 2 |
| = | 230 | × | 1 2 |
| = | 115 | × | 1 |
| x | = | 115 |