| 5 | ÷ | 12 | × | X | + | 4 | = | ( | X | + | 4 | ) | × | 6 | ÷ | 13 |
| 方程左边 = | 5 12 | X | + | 4 |
5 12 | X | + | 4 | = | ( | X | + | 4 | ) | × | 6 | ÷ | 13 |
| 方程右边 = | ( | X | + | 4 | ) | × | 6 13 |
5 12 | X | + | 4 | = | ( | X | + | 4 | ) | × | 6 13 |
| 方程右边 = | X | × | 6 13 | + | 4 | × | 6 13 |
| = | X | × | 6 13 | + | 24 13 |
5 12 | X | + | 4 | = | 6 13 | X | + | 24 13 |
5 12 | X | − | 6 13 | X | = | 24 13 | − | 4 |
| - | 7 156 | X | = | 24 13 | − | 4 |
| - | 7 156 | X | = | - | 28 13 |
28 13 | = | 7 156 | X |
7 156 | X | = | 28 13 |
| X | = | 28 13 | ÷ | 7 156 |
| = | 28 13 | × | 156 7 |
| = | 4 | × | 12 |
| X | = | 48 |