| 8 | − | 2 | ( | x | − | 7 | ) | = | x | − | ( | x | − | 4 | ) |
| Left side of the equation = | 8 | − | 2 | x | + | 2 | × | 7 |
| = | 8 | − | 2 | x | + | 14 |
| = | 22 | − | 2 | x |
| 22 | − | 2 | x | = | x | − | ( | x | − | 4 | ) |
| Right side of the equation = | x | − | x | + | 4 |
| = | 0 | x | + | 4 |
| 22 | − | 2 | x | = | 4 |
| - | 2 | x | = | 4 | − | 22 |
| - | 2 | x | = | - | 18 |
| 18 | = | 2 | x |
| 2 | x | = | 18 |
| x | = | 18 | ÷ | 2 |
| = | 18 | × | 1 2 |
| = | 9 | × | 1 |
| x | = | 9 |