| ( | 21 | ÷ | x | − | 4 | ) | × | 3 2 | = | ( | 22 | ÷ | x | − | 4 | ) |
| 21 | ÷ | x | × | 3 2 | − | 4 | × | 3 2 | = | ( | 22 | ÷ | x | − | 4 | ) |
| 21 | ÷ | x | × | 3 2 | − | 4 | × | 3 2 | = | 22 | ÷ | x | − | 4 |
63 2 | ÷ | x | − | 6 | = | 22 | ÷ | x | − | 4 |
| 方程两边同时乘以: | x |
63 2 | − | 6 | x | = | 22 | ÷ | 1 | × | 1 | − | 4 | x |
| - | 6 | x | + | 4 | x | = | 22 | ÷ | 1 | × | 1 | − | 63 2 |
| - | 6 | x | + | 4 | x | = | 22 | − | 63 2 |
| - | 2 | x | = | 22 | − | 63 2 |
| - | 2 | x | = | - | 19 2 |
19 2 | = | 2 | x |
| 2 | x | = | 19 2 |
| x | = | 19 2 | ÷ | 2 |
| = | 19 2 | × | 1 2 |
| x | = | 19 4 |
| x | = | 4.75 |