| 12 | ÷ | ( | x | + | 3 | ) | = | 12 | ÷ | ( | 2 | x | + | 4 | ) |
| Multiply both sides of the equation by: | ( | x | + | 3 | ) | , | ( | 2 | x | + | 4 | ) |
| 12 | ( | 2 | x | + | 4 | ) | = | 12 | ( | x | + | 3 | ) |
| 12 | × | 2 | x | + | 12 | × | 4 | = | 12 | ( | x | + | 3 | ) |
| 12 | × | 2 | x | + | 12 | × | 4 | = | 12 | x | + | 12 | × | 3 |
| 24 | x | + | 48 | = | 12 | x | + | 36 |
| 24 | x | − | 12 | x | = | 36 | − | 48 |
| 12 | x | = | 36 | − | 48 |
| 12 | x | = | - | 12 |
| x | = | - | 12 | ÷ | 12 |
| = | - | 12 | × | 1 12 |
| = | - | 1 | × | 1 |
| x | = | - | 1 |