| 700 | ÷ | x | = | 900 | ÷ | ( | x | + | 20 | ) |
| Multiply both sides of the equation by: | x | , | ( | x | + | 20 | ) |
| 700 | ( | x | + | 20 | ) | = | 900 | x |
| 700 | x | + | 700 | × | 20 | = | 900 | x |
| 700 | x | + | 14000 | = | 900 | x |
| 700 | x | − | 900 | x | = | - | 14000 |
| - | 200 | x | = | - | 14000 |
| 14000 | = | 200 | x |
| 200 | x | = | 14000 |
| x | = | 14000 | ÷ | 200 |
| = | 14000 | × | 1 200 |
| = | 70 | × | 1 |
| x | = | 70 |