| ( | 191 | + | x | ) | ÷ | ( | 395 | + | x | ) | = | 1 2 |
| 方程两边同时乘以: | ( | 395 | + | x | ) |
| ( | 191 | + | x | ) | = | 1 2 | ( | 395 | + | x | ) |
| 191 | + | x | = | 1 2 | ( | 395 | + | x | ) |
| 191 | + | x | = | 1 2 | × | 395 | + | 1 2 | x |
| 191 | + | x | = | 395 2 | + | 1 2 | x |
| x | − | 1 2 | x | = | 395 2 | − | 191 |
1 2 | x | = | 395 2 | − | 191 |
1 2 | x | = | 13 2 |
| x | = | 13 2 | ÷ | 1 2 |
| = | 13 2 | × | 2 |
| = | 13 | × | 1 |
| x | = | 13 |