| ( | 1 | ÷ | 10 | + | 1 | ÷ | 12 | ) | × | 3 | + | ( | 1 | ÷ | 12 | + | 1 | ÷ | 15 | ) | x | = | 1 |
| 方程左边 = | 1 | ÷ | 10 | × | 3 | + | 1 | ÷ | 12 | × | 3 | + | ( | 1 | ÷ | 12 | + | 1 | ÷ | 15 | ) | x |
| = | 3 10 | + | 1 4 | + | ( | 1 | ÷ | 12 | + | 1 | ÷ | 15 | ) | x |
| = | 11 20 | + | ( | 1 | ÷ | 12 | + | 1 | ÷ | 15 | ) | x |
| = | 11 20 | + | 1 | ÷ | 12 | × | x | + | 1 | ÷ | 15 | × | x |
| = | 11 20 | + | 1 12 | x | + | 1 15 | x |
| = | 11 20 | + | 3 20 | x |
11 20 | + | 3 20 | x | = | 1 |
3 20 | x | = | 1 | − | 11 20 |
3 20 | x | = | 9 20 |
| x | = | 9 20 | ÷ | 3 20 |
| = | 9 20 | × | 20 3 |
| = | 3 | × | 1 |
| x | = | 3 |