| 450 | ÷ | ( | X | + | 10 | ) | + | 1 2 | = | 440 | ÷ | X |
| 方程两边同时乘以: | ( | X | + | 10 | ) | , | X |
| 450 | X | + | 1 2 | ( | X | + | 10 | ) | X | = | 440 | ( | X | + | 10 | ) |
| 450 | X | + | 1 2 | X | X | + | 1 2 | × | 10 | X | = | 440 | ( | X | + | 10 | ) |
| 450 | X | + | 1 2 | X | X | + | 1 2 | × | 10 | X | = | 440 | X | + | 440 | × | 10 |
| 450 | X | + | 1 2 | X | X | + | 5 | X | = | 440 | X | + | 4400 |
| 455 | X | + | 1 2 | X | X | = | 440 | X | + | 4400 |