| 1000 | ÷ | ( | 1000 | + | x | ) | = | 7 10 |
| Multiply both sides of the equation by: | ( | 1000 | + | x | ) |
| 1000 | = | 7 10 | ( | 1000 | + | x | ) |
| 1000 | = | 7 10 | × | 1000 | + | 7 10 | x |
| 1000 | = | 700 | + | 7 10 | x |
| - | 7 10 | x | = | 700 | − | 1000 |
| - | 7 10 | x | = | - | 300 |
| 300 | = | 7 10 | x |
7 10 | x | = | 300 |
| x | = | 300 | ÷ | 7 10 |
| = | 300 | × | 10 7 |
| x | = | 3000 7 |
| x | = | 428.571429 |