11 50 | = | 5 200 | + | 13 10 | ( | X | − | 5 200 | ) |
| 方程右边 = | 5 200 | + | 13 10 | X | − | 13 10 | × | 5 200 |
| = | 5 200 | + | 13 10 | X | − | 13 400 |
| = | - | 3 400 | + | 13 10 | X |
11 50 | = | - | 3 400 | + | 13 10 | X |
| - | 13 10 | X | = | - | 3 400 | − | 11 50 |
| - | 13 10 | X | = | - | 91 400 |
91 400 | = | 13 10 | X |
13 10 | X | = | 91 400 |
| X | = | 91 400 | ÷ | 13 10 |
| = | 91 400 | × | 10 13 |
| = | 7 40 | × | 1 |
| X | = | 7 40 |
| X | = | 0.175 |