| 10 | = | 100 | ( | x | − | 216 | ) | ÷ | ( | x | × | 700 | ÷ | 100 | ) |
| Multiply both sides of the equation by: | ( | x | × | 700 | ÷ | 100 | ) |
| 10 | ( | x | × | 700 | ÷ | 100 | ) | = | 100 | ( | x | − | 216 | ) |
| 10 | x | × | 700 | ÷ | 100 | = | 100 | ( | x | − | 216 | ) |
| 10 | x | × | 700 | ÷ | 100 | = | 100 | x | − | 100 | × | 216 |
| 70 | x | = | 100 | x | − | 21600 |
| 70 | x | − | 100 | x | = | - | 21600 |
| - | 30 | x | = | - | 21600 |
| 21600 | = | 30 | x |
| 30 | x | = | 21600 |
| x | = | 21600 | ÷ | 30 |
| = | 21600 | × | 1 30 |
| = | 720 | × | 1 |
| x | = | 720 |