| - | 12 | ( | 5 | x | − | 11 | ) | + | 8 | ( | - | 2 | x | + | 1 | ) | + | 9 | = | - | 3 |
| Left side of the equation = | - | 12 | × | 5 | x | + | 12 | × | 11 | + | 8 | ( | - | 2 | x | + | 1 | ) | + | 9 |
| = | - | 60 | x | + | 132 | + | 8 | ( | - | 2 | x | + | 1 | ) | + | 9 |
| = | - | 60 | x | + | 141 | + | 8 | ( | - | 2 | x | + | 1 | ) |
| = | - | 60 | x | + | 141 | − | 8 | × | 2 | x | + | 8 | × | 1 |
| = | - | 60 | x | + | 141 | − | 16 | x | + | 8 |
| = | - | 76 | x | + | 149 |
| - | 76 | x | + | 149 | = | - | 3 |
| - | 76 | x | = | - | 3 | − | 149 |
| - | 76 | x | = | - | 152 |
| 152 | = | 76 | x |
| 76 | x | = | 152 |
| x | = | 152 | ÷ | 76 |
| = | 152 | × | 1 76 |
| = | 2 | × | 1 |
| x | = | 2 |