| ( | 21284 | + | X | ) | ÷ | ( | 45721 | + | X | ) | = | 1 2 |
| 方程两边同时乘以: | ( | 45721 | + | X | ) |
| ( | 21284 | + | X | ) | = | 1 2 | ( | 45721 | + | X | ) |
| 21284 | + | X | = | 1 2 | ( | 45721 | + | X | ) |
| 21284 | + | X | = | 1 2 | × | 45721 | + | 1 2 | X |
| 21284 | + | X | = | 45721 2 | + | 1 2 | X |
| X | − | 1 2 | X | = | 45721 2 | − | 21284 |
1 2 | X | = | 45721 2 | − | 21284 |
1 2 | X | = | 3153 2 |
| X | = | 3153 2 | ÷ | 1 2 |
| = | 3153 2 | × | 2 |
| = | 3153 | × | 1 |
| X | = | 3153 |