| 3 | = | 100 | ( | x | − | 216 | ) | ÷ | ( | x | × | 700 | ÷ | 100 | ) |
| 方程两边同时乘以: | ( | x | × | 700 | ÷ | 100 | ) |
| 3 | ( | x | × | 700 | ÷ | 100 | ) | = | 100 | ( | x | − | 216 | ) |
| 3 | x | × | 700 | ÷ | 100 | = | 100 | ( | x | − | 216 | ) |
| 3 | x | × | 700 | ÷ | 100 | = | 100 | x | − | 100 | × | 216 |
| 21 | x | = | 100 | x | − | 21600 |
| 21 | x | − | 100 | x | = | - | 21600 |
| - | 79 | x | = | - | 21600 |
| 21600 | = | 79 | x |
| 79 | x | = | 21600 |
| x | = | 21600 | ÷ | 79 |
| = | 21600 | × | 1 79 |
| x | = | 21600 79 |
| x | = | 273.417722 |