| ( | 4 | − | a | ) | ( | - | 8 | ÷ | a | − | 2 | ) | = | 30 |
| 4 | ( | - | 8 | ÷ | a | − | 2 | ) | − | a | ( | - | 8 | ÷ | a | − | 2 | ) | = | 30 |
| - | 4 | × | 8 | ÷ | a | − | 4 | × | 2 | − | a | ( | - | 8 | ÷ | a | − | 2 | ) | = | 30 |
| - | 32 | ÷ | a | − | 8 | − | a | ( | - | 8 | ÷ | a | − | 2 | ) | = | 30 |
| Multiply both sides of the equation by: | a |
| - | 32 | − | 8 | a | − | a | ( | - | 8 | ÷ | a | − | 2 | ) | a | = | 30 | a |
| - | 32 | − | 8 | a | + | a | × | 8 | ÷ | a | × | a | + | a | × | 2 | a | = | 30 | a |