| 5 | ( | x | + | 21 | − | 1 | ) | = | 6 | ( | x | − | 1 | ) |
| Left side of the equation = | 5 | x | + | 5 | × | 21 | − | 5 | × | 1 |
| = | 5 | x | + | 105 | − | 5 |
| = | 5 | x | + | 100 |
| 5 | x | + | 100 | = | 6 | ( | x | − | 1 | ) |
| Right side of the equation = | 6 | x | − | 6 | × | 1 |
| = | 6 | x | − | 6 |
| 5 | x | + | 100 | = | 6 | x | − | 6 |
| 5 | x | − | 6 | x | = | - | 6 | − | 100 |
| - | x | = | - | 6 | − | 100 |
| - | x | = | - | 6 | − | 100 |
| - | x | = | - | 106 |
| 106 | = | x |
| x | = | 106 |