| 30 | + | X | = | 93 100 | ( | 15 | + | X | ) |
| 方程右边 = | 93 100 | × | 15 | + | 93 100 | X |
| = | 279 20 | + | 93 100 | X |
| 30 | + | X | = | 279 20 | + | 93 100 | X |
| X | − | 93 100 | X | = | 279 20 | − | 30 |
7 100 | X | = | 279 20 | − | 30 |
7 100 | X | = | - | 321 20 |
| X | = | - | 321 20 | ÷ | 7 100 |
| = | - | 321 20 | × | 100 7 |
| = | - | 321 | × | 5 7 |
| X | = | - | 1605 7 |
| X | = | - 229.285714 |