| ( | 400 | − | x | ) | ( | 8 | + | 10 | ÷ | x | ) | = | 5600 |
| 400 | ( | 8 | + | 10 | ÷ | x | ) | − | x | ( | 8 | + | 10 | ÷ | x | ) | = | 5600 |
| 400 | × | 8 | + | 400 | × | 10 | ÷ | x | − | x | ( | 8 | + | 10 | ÷ | x | ) | = | 5600 |
| 3200 | + | 4000 | ÷ | x | − | x | ( | 8 | + | 10 | ÷ | x | ) | = | 5600 |
| Multiply both sides of the equation by: | x |
| 3200 | x | + | 4000 | − | x | ( | 8 | + | 10 | ÷ | x | ) | x | = | 5600 | x |
| 3200 | x | + | 4000 | − | x | × | 8 | x | − | x | × | 10 | ÷ | x | × | x | = | 5600 | x |