| ( | 1 10 | x | + | 1 20 | ) | ÷ | 1 5 | − | ( | 1 5 | x | − | 1 20 | ) | ÷ | 1 2 | + | 5 | ÷ | 4 | = | 0 |
| 方程左边 = | ( | 1 10 | x | + | 1 20 | ) | × | 5 | − | ( | 1 5 | x | − | 1 20 | ) | × | 2 | + | 5 4 |
| ( | 1 10 | x | + | 1 20 | ) | × | 5 | − | ( | 1 5 | x | − | 1 20 | ) | × | 2 | + | 5 4 | = | 0 |
| 方程左边 = | 1 10 | x | × | 5 | + | 1 20 | × | 5 | − | ( | 1 5 | x | − | 1 20 | ) | × | 2 | + | 5 4 |
| = | 1 2 | x | + | 1 4 | − | ( | 1 5 | x | − | 1 20 | ) | × | 2 | + | 5 4 |
| = | 1 2 | x | + | 3 2 | − | ( | 1 5 | x | − | 1 20 | ) | × | 2 |
| = | 1 2 | x | + | 3 2 | − | 1 5 | x | × | 2 | + | 1 20 | × | 2 |
| = | 1 2 | x | + | 3 2 | − | 2 5 | x | + | 1 10 |
| = | 1 10 | x | + | 8 5 |
1 10 | x | + | 8 5 | = | 0 |
1 10 | x | = | 0 | − | 8 5 |
1 10 | x | = | - | 8 5 |
| x | = | - | 8 5 | ÷ | 1 10 |
| = | - | 8 5 | × | 10 |
| = | - | 8 | × | 2 |
| x | = | - | 16 |