| ( | 25 | + | x | ) | ÷ | ( | 51 | + | x | ) | = | 11 20 |
| 方程两边同时乘以: | ( | 51 | + | x | ) |
| ( | 25 | + | x | ) | = | 11 20 | ( | 51 | + | x | ) |
| 25 | + | x | = | 11 20 | ( | 51 | + | x | ) |
| 25 | + | x | = | 11 20 | × | 51 | + | 11 20 | x |
| 25 | + | x | = | 561 20 | + | 11 20 | x |
| x | − | 11 20 | x | = | 561 20 | − | 25 |
9 20 | x | = | 561 20 | − | 25 |
9 20 | x | = | 61 20 |
| x | = | 61 20 | ÷ | 9 20 |
| = | 61 20 | × | 20 9 |
| = | 61 | × | 1 9 |
| x | = | 61 9 |
| x | = | 6.777778 |