| 2 | ÷ | ( | 15 | − | x | ) | = | 7 4 | ÷ | ( | x | + | 15 4 | ) |
| 方程两边同时乘以: | ( | 15 | − | x | ) | , | ( | x | + | 15 4 | ) |
| 2 | ( | x | + | 15 4 | ) | = | 7 4 | ( | 15 | − | x | ) |
| 2 | x | + | 2 | × | 15 4 | = | 7 4 | ( | 15 | − | x | ) |
| 2 | x | + | 2 | × | 15 4 | = | 7 4 | × | 15 | − | 7 4 | x |
| 2 | x | + | 15 2 | = | 105 4 | − | 7 4 | x |
| 2 | x | + | 7 4 | x | = | 105 4 | − | 15 2 |
15 4 | x | = | 105 4 | − | 15 2 |
15 4 | x | = | 75 4 |
| x | = | 75 4 | ÷ | 15 4 |
| = | 75 4 | × | 4 15 |
| = | 5 | × | 1 |
| x | = | 5 |