| ( | x | − | 40 | ) | ÷ | ( | 7 | ÷ | 8 | × | x | + | 40 | ) | = | 3 | ÷ | 2 |
| Multiply both sides of the equation by: | ( | 7 | ÷ | 8 | × | x | + | 40 | ) |
| ( | x | − | 40 | ) | = | 3 | ÷ | 2 | × | ( | 7 | ÷ | 8 | × | x | + | 40 | ) |
| x | − | 40 | = | 3 | ÷ | 2 | × | ( | 7 | ÷ | 8 | × | x | + | 40 | ) |
| x | − | 40 | = | 3 | ÷ | 2 | × | 7 | ÷ | 8 | × | x | + | 3 | ÷ | 2 | × | 40 |
| x | − | 40 | = | 21 16 | x | + | 60 |
| x | − | 21 16 | x | = | 60 | + | 40 |
| - | 5 16 | x | = | 60 | + | 40 |
| - | 5 16 | x | = | 100 |
| - | 100 | = | 5 16 | x |
5 16 | x | = | - | 100 |
| x | = | - | 100 | ÷ | 5 16 |
| = | - | 100 | × | 16 5 |
| = | - | 20 | × | 16 |
| x | = | - | 320 |