| 400 | ÷ | x | = | 2 | ( | 160 | ÷ | x | − | 4 5 | ) |
| Multiply both sides of the equation by: | x |
| 400 | = | 2 | ( | 160 | ÷ | x | − | 4 5 | ) | x |
| 400 | = | 2 | × | 160 | ÷ | x | × | x | − | 2 | × | 4 5 | x |
| 400 | = | 320 | ÷ | x | × | x | − | 8 5 | x |
8 5 | x | = | 320 | ÷ | 1 | × | 1 | − | 400 |
8 5 | x | = | 320 | − | 400 |
8 5 | x | = | - | 80 |
| x | = | - | 80 | ÷ | 8 5 |
| = | - | 80 | × | 5 8 |
| = | - | 10 | × | 5 |
| x | = | - | 50 |