| ( | 1 | ÷ | 10 | ) | + | ( | X | ÷ | 20 | ) | + | ( | 16 | − | 3 | − | X | ) | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) | = | 1 |
| 方程左边 = | 1 | ÷ | 10 | + | ( | X | ÷ | 20 | ) | + | ( | 16 | − | 3 | − | X | ) | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) |
| = | 1 10 | + | ( | X | ÷ | 20 | ) | + | ( | 16 | − | 3 | − | X | ) | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) |
| = | 1 10 | + | X | ÷ | 20 | + | ( | 16 | − | 3 | − | X | ) | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) |
| = | 1 10 | + | 1 20 | X | + | 16 | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) | − | 3 | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) | − | X | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) |
| = | 1 10 | + | 1 20 | X | + | 16 | × | 1 | ÷ | 20 | + | 16 | × | 1 | ÷ | 30 | − | 3 | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) | − | X |
| = | 1 10 | + | 1 20 | X | + | 4 5 | + | 8 15 | − | 3 | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) | − | X | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) |
| = | 43 30 | + | 1 20 | X | − | 3 | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) | − | X | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) |
| = | 43 30 | + | 1 20 | X | − | 3 | × | 1 | ÷ | 20 | − | 3 | × | 1 | ÷ | 30 | − | X | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) |
| = | 43 30 | + | 1 20 | X | − | 3 20 | − | 1 10 | − | X | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) |
| = | 71 60 | + | 1 20 | X | − | X | ( | 1 | ÷ | 20 | + | 1 | ÷ | 30 | ) |
| = | 71 60 | + | 1 20 | X | − | X | × | 1 | ÷ | 20 | − | X | × | 1 | ÷ | 30 |
| = | 71 60 | + | 1 20 | X | − | X | × | 1 20 | − | X | × | 1 30 |
| = | 71 60 | − | 1 30 | X |
71 60 | − | 1 30 | X | = | 1 |
| - | 1 30 | X | = | 1 | − | 71 60 |
| - | 1 30 | X | = | - | 11 60 |
11 60 | = | 1 30 | X |
1 30 | X | = | 11 60 |
| X | = | 11 60 | ÷ | 1 30 |
| = | 11 60 | × | 30 |
| = | 11 2 | × | 1 |
| X | = | 11 2 |
| X | = | 5.5 |