| 50 | x | + | 30 | = | 60 | ( | x | − | 1 | ) | − | 20 |
| Right side of the equation = | 60 | x | − | 60 | × | 1 | − | 20 |
| = | 60 | x | − | 60 | − | 20 |
| = | 60 | x | − | 80 |
| 50 | x | + | 30 | = | 60 | x | − | 80 |
| 50 | x | − | 60 | x | = | - | 80 | − | 30 |
| - | 10 | x | = | - | 80 | − | 30 |
| - | 10 | x | = | - | 110 |
| 110 | = | 10 | x |
| 10 | x | = | 110 |
| x | = | 110 | ÷ | 10 |
| = | 110 | × | 1 10 |
| = | 11 | × | 1 |
| x | = | 11 |