| 480 | x | − | 100 | ( | x | + | 1 | ) | = | 50 | ( | 7 | x | + | 1 | ) |
| Left side of the equation = | 480 | x | − | 100 | x | − | 100 | × | 1 |
| = | 480 | x | − | 100 | x | − | 100 |
| = | 380 | x | − | 100 |
| 380 | x | − | 100 | = | 50 | ( | 7 | x | + | 1 | ) |
| Right side of the equation = | 50 | × | 7 | x | + | 50 | × | 1 |
| = | 350 | x | + | 50 |
| 380 | x | − | 100 | = | 350 | x | + | 50 |
| 380 | x | − | 350 | x | = | 50 | + | 100 |
| 30 | x | = | 50 | + | 100 |
| 30 | x | = | 150 |
| x | = | 150 | ÷ | 30 |
| = | 150 | × | 1 30 |
| = | 5 | × | 1 |
| x | = | 5 |