| ( | x | + | 1 | ) | × | 7 | = | ( | x | − | 1 | ) | × | 8 |
| Left side of the equation = | x | × | 7 | + | 1 | × | 7 |
| = | x | × | 7 | + | 7 |
| 7 | x | + | 7 | = | ( | x | − | 1 | ) | × | 8 |
| Right side of the equation = | x | × | 8 | − | 1 | × | 8 |
| = | x | × | 8 | − | 8 |
| 7 | x | + | 7 | = | 8 | x | − | 8 |
| 7 | x | − | 8 | x | = | - | 8 | − | 7 |
| - | x | = | - | 8 | − | 7 |
| - | x | = | - | 8 | − | 7 |
| - | x | = | - | 15 |
| 15 | = | x |
| x | = | 15 |