| 5 | ( | 1 | ÷ | 15 | + | 1 | ÷ | 12 | ) | + | x | ( | 1 | ÷ | 12 | ) | = | 1 |
| 方程左边 = | 5 | × | 1 | ÷ | 15 | + | 5 | × | 1 | ÷ | 12 | + | x | ( | 1 | ÷ | 12 | ) |
| = | 1 3 | + | 5 12 | + | x | ( | 1 | ÷ | 12 | ) |
| = | 3 4 | + | x | ( | 1 | ÷ | 12 | ) |
| = | 3 4 | + | x | × | 1 | ÷ | 12 |
| = | 3 4 | + | x | × | 1 12 |
3 4 | + | 1 12 | x | = | 1 |
1 12 | x | = | 1 | − | 3 4 |
1 12 | x | = | 1 4 |
| x | = | 1 4 | ÷ | 1 12 |
| = | 1 4 | × | 12 |
| = | 1 | × | 3 |
| x | = | 3 |