| 2 | ÷ | 5 | × | x | + | 100 | = | 5 | ÷ | 12 | × | ( | x | + | 100 | + | 100 | ) |
| 方程左边 = | 2 5 | x | + | 100 |
2 5 | x | + | 100 | = | 5 | ÷ | 12 | × | ( | x | + | 100 | + | 100 | ) |
| 方程右边 = | 5 12 | ( | x | + | 100 | + | 100 | ) |
2 5 | x | + | 100 | = | 5 12 | ( | x | + | 100 | + | 100 | ) |
| 方程右边 = | 5 12 | x | + | 5 12 | × | 100 | + | 5 12 | × | 100 |
| = | 5 12 | x | + | 125 3 | + | 125 3 |
| = | 5 12 | x | + | 250 3 |
2 5 | x | + | 100 | = | 5 12 | x | + | 250 3 |
2 5 | x | − | 5 12 | x | = | 250 3 | − | 100 |
| - | 1 60 | x | = | 250 3 | − | 100 |
| - | 1 60 | x | = | - | 50 3 |
50 3 | = | 1 60 | x |
1 60 | x | = | 50 3 |
| x | = | 50 3 | ÷ | 1 60 |
| = | 50 3 | × | 60 |
| = | 50 | × | 20 |
| x | = | 1000 |