| 18 | x | ÷ | ( | 100 | − | x | ) | = | 6 | ( | 100 | − | x | ) | ÷ | x |
| Multiply both sides of the equation by: | ( | 100 | − | x | ) | , | x |
| 18 | x | x | = | 6 | ( | 100 | − | x | ) | ( | 100 | − | x | ) |
| 18 | x | x | = | 6 | × | 100 | ( | 100 | − | x | ) | − | 6 | x | ( | 100 | − | x | ) |
| 18 | x | x | = | 600 | ( | 100 | − | x | ) | − | 6 | x | ( | 100 | − | x | ) |
| 18 | x | x | = | 600 | × | 100 | − | 600 | x | − | 6 | x | ( | 100 | − | x | ) |
| 18 | x | x | = | 60000 | − | 600 | x | − | 6 | x | ( | 100 | − | x | ) |
| 18 | x | x | = | 60000 | − | 600 | x | − | 6 | x | × | 100 | + | 6 | x | x |
| 18 | x | x | = | 60000 | − | 600 | x | − | 600 | x | + | 6 | x | x |
| 18 | x | x | = | 60000 | − | 1200 | x | + | 6 | x | x |