| ( | 35 | + | x | ) | ÷ | ( | 15 | + | x | ) | = | 5 | ÷ | 3 |
| Multiply both sides of the equation by: | ( | 15 | + | x | ) |
| ( | 35 | + | x | ) | = | 5 | ÷ | 3 | × | ( | 15 | + | x | ) |
| 35 | + | x | = | 5 | ÷ | 3 | × | ( | 15 | + | x | ) |
| 35 | + | x | = | 5 | ÷ | 3 | × | 15 | + | 5 | ÷ | 3 | × | x |
| 35 | + | x | = | 25 | + | 5 3 | x |
| x | − | 5 3 | x | = | 25 | − | 35 |
| - | 2 3 | x | = | 25 | − | 35 |
| - | 2 3 | x | = | - | 10 |
| 10 | = | 2 3 | x |
2 3 | x | = | 10 |
| x | = | 10 | ÷ | 2 3 |
| = | 10 | × | 3 2 |
| = | 5 | × | 3 |
| x | = | 15 |