| ( | 18 5 | + | 41 50 | X | ) | ÷ | ( | 100 | + | X | ) | = | 3 10 |
| 方程两边同时乘以: | ( | 100 | + | X | ) |
| ( | 18 5 | + | 41 50 | X | ) | = | 3 10 | ( | 100 | + | X | ) |
18 5 | + | 41 50 | X | = | 3 10 | ( | 100 | + | X | ) |
18 5 | + | 41 50 | X | = | 3 10 | × | 100 | + | 3 10 | X |
18 5 | + | 41 50 | X | = | 30 | + | 3 10 | X |
41 50 | X | − | 3 10 | X | = | 30 | − | 18 5 |
13 25 | X | = | 30 | − | 18 5 |
13 25 | X | = | 132 5 |
| X | = | 132 5 | ÷ | 13 25 |
| = | 132 5 | × | 25 13 |
| = | 132 | × | 5 13 |
| X | = | 660 13 |
| X | = | 50.769231 |