| 50 | = | 100 | x | ÷ | ( | 100 | + | x | ) |
| Multiply both sides of the equation by: | ( | 100 | + | x | ) |
| 50 | ( | 100 | + | x | ) | = | 100 | x |
| 50 | × | 100 | + | 50 | x | = | 100 | x |
| 5000 | + | 50 | x | = | 100 | x |
| 50 | x | − | 100 | x | = | - | 5000 |
| - | 50 | x | = | - | 5000 |
| 5000 | = | 50 | x |
| 50 | x | = | 5000 |
| x | = | 5000 | ÷ | 50 |
| = | 5000 | × | 1 50 |
| = | 100 | × | 1 |
| x | = | 100 |