| 2 | ( | ( | 1 | ÷ | 10 | ) | + | ( | 1 | ÷ | 15 | ) | ) | + | ( | 1 | ÷ | 15 | ) | = | x |
| 方程左边 = | 2 | ( | 1 | ÷ | 10 | ) | + | 2 | ( | 1 | ÷ | 15 | ) | + | ( | 1 | ÷ | 15 | ) |
| = | 2 | × | 1 | ÷ | 10 | + | 2 | ( | 1 | ÷ | 15 | ) | + | ( | 1 | ÷ | 15 | ) |
| = | 1 5 | + | 2 | ( | 1 | ÷ | 15 | ) | + | ( | 1 | ÷ | 15 | ) |
| = | 1 5 | + | 2 | × | 1 | ÷ | 15 | + | ( | 1 | ÷ | 15 | ) |
| = | 1 5 | + | 2 15 | + | ( | 1 | ÷ | 15 | ) |
| = | 1 3 | + | ( | 1 | ÷ | 15 | ) |
| = | 1 3 | + | 1 | ÷ | 15 |
| = | 1 3 | + | 1 15 |
| = | 2 5 |
2 5 | = | x |
| - | x | = | - | 2 5 |
2 5 | = | x |
| x | = | 2 5 |