| 2 | ( | 9 | − | 2 | X | × | 1 | ) | = | 3 | ( | 11 | − | 2 | X | × | 2 | ) |
| 方程左边 = | 2 | × | 9 | − | 2 | × | 2 | X | × | 1 |
| = | 18 | − | 4 | X |
| 18 | − | 4 | X | = | 3 | ( | 11 | − | 2 | X | × | 2 | ) |
| 方程右边 = | 3 | × | 11 | − | 3 | × | 2 | X | × | 2 |
| = | 33 | − | 12 | X |
| 18 | − | 4 | X | = | 33 | − | 12 | X |
| - | 4 | X | + | 12 | X | = | 33 | − | 18 |
| 8 | X | = | 33 | − | 18 |
| 8 | X | = | 15 |
| X | = | 15 | ÷ | 8 |
| = | 15 | × | 1 8 |
| X | = | 15 8 |
| X | = | 1.875 |