| ( | 2 | x | ÷ | ( | 400 | − | x | ) | + | 2 | ) | x | = | 1200 |
| 2 | x | ÷ | ( | 400 | − | x | ) | × | x | + | 2 | x | = | 1200 |
| Multiply both sides of the equation by: | ( | 400 | − | x | ) |
| 2 | x | x | + | 2 | x | ( | 400 | − | x | ) | = | 1200 | ( | 400 | − | x | ) |
| 2 | x | x | + | 2 | x | × | 400 | − | 2 | x | x | = | 1200 | ( | 400 | − | x | ) |
| 2 | x | x | + | 2 | x | × | 400 | − | 2 | x | x | = | 1200 | × | 400 | − | 1200 | x |
| 2 | x | x | + | 800 | x | − | 2 | x | x | = | 480000 | − | 1200 | x |