| 11 | ( | x | + | 6 | ) | − | 3 | ( | x | + | 9 | ) | + | 11 | = | 10 |
| Left side of the equation = | 11 | x | + | 11 | × | 6 | − | 3 | ( | x | + | 9 | ) | + | 11 |
| = | 11 | x | + | 66 | − | 3 | ( | x | + | 9 | ) | + | 11 |
| = | 11 | x | + | 77 | − | 3 | ( | x | + | 9 | ) |
| = | 11 | x | + | 77 | − | 3 | x | − | 3 | × | 9 |
| = | 11 | x | + | 77 | − | 3 | x | − | 27 |
| = | 8 | x | + | 50 |
| 8 | x | + | 50 | = | 10 |
| 8 | x | = | 10 | − | 50 |
| 8 | x | = | - | 40 |
| x | = | - | 40 | ÷ | 8 |
| = | - | 40 | × | 1 8 |
| = | - | 5 | × | 1 |
| x | = | - | 5 |