| 120 | × | 8 | ÷ | ( | 120 | − | 100 | ) | × | 100 | = | x |
| Multiply both sides of the equation by: | ( | 120 | − | 100 | ) |
| 120 | × | 8 | × | 100 | = | x | ( | 120 | − | 100 | ) |
| 120 | × | 8 | × | 100 | = | x | × | 120 | − | x | × | 100 |
| 96000 | = | x | × | 120 | − | x | × | 100 |
| 96000 | = | 20 | x |
| - | 20 | x | = | - | 96000 |
| 96000 | = | 20 | x |
| 20 | x | = | 96000 |
| x | = | 96000 | ÷ | 20 |
| = | 96000 | × | 1 20 |
| = | 4800 | × | 1 |
| x | = | 4800 |