| 1 | ÷ | 60 | × | x | + | 1 | ÷ | 60 | × | 2 | ( | x | + | 15 | ) | = | 1 |
| 方程左边 = | 1 60 | x | + | 1 30 | ( | x | + | 15 | ) |
1 60 | x | + | 1 30 | ( | x | + | 15 | ) | = | 1 |
| 方程左边 = | 1 60 | x | + | 1 30 | x | + | 1 30 | × | 15 |
| = | 1 60 | x | + | 1 30 | x | + | 1 2 |
| = | 1 20 | x | + | 1 2 |
1 20 | x | + | 1 2 | = | 1 |
1 20 | x | = | 1 | − | 1 2 |
1 20 | x | = | 1 2 |
| x | = | 1 2 | ÷ | 1 20 |
| = | 1 2 | × | 20 |
| = | 1 | × | 10 |
| x | = | 10 |