| 3 | ( | - | 13 | x | − | 4 | ) | + | 2 | ( | 6 | x | − | 7 | ) | + | 8 | = | - | 18 |
| Left side of the equation = | - | 3 | × | 13 | x | − | 3 | × | 4 | + | 2 | ( | 6 | x | − | 7 | ) | + | 8 |
| = | - | 39 | x | − | 12 | + | 2 | ( | 6 | x | − | 7 | ) | + | 8 |
| = | - | 39 | x | − | 4 | + | 2 | ( | 6 | x | − | 7 | ) |
| = | - | 39 | x | − | 4 | + | 2 | × | 6 | x | − | 2 | × | 7 |
| = | - | 39 | x | − | 4 | + | 12 | x | − | 14 |
| = | - | 27 | x | − | 18 |
| - | 27 | x | − | 18 | = | - | 18 |
| - | 27 | x | = | - | 18 | + | 18 |
| - | 27 | x | = | - | 0 |
| 0 | = | 27 | x |
| 27 | x | = | 0 |
| x | = | 0 | ÷ | 27 |
| = | 0 | × | 1 27 |
| x | = | 0 |