| ( | 187 | + | x | ) | ÷ | ( | 389 | + | x | ) | = | 1 2 |
| Multiply both sides of the equation by: | ( | 389 | + | x | ) |
| ( | 187 | + | x | ) | = | 1 2 | ( | 389 | + | x | ) |
| 187 | + | x | = | 1 2 | ( | 389 | + | x | ) |
| 187 | + | x | = | 1 2 | × | 389 | + | 1 2 | x |
| 187 | + | x | = | 389 2 | + | 1 2 | x |
| x | − | 1 2 | x | = | 389 2 | − | 187 |
1 2 | x | = | 389 2 | − | 187 |
1 2 | x | = | 15 2 |
| x | = | 15 2 | ÷ | 1 2 |
| = | 15 2 | × | 2 |
| = | 15 | × | 1 |
| x | = | 15 |