| ( | 42420 | + | 43 25 | x | ) | ÷ | ( | 20000 | + | x | ) | = | 9 5 |
| 方程两边同时乘以: | ( | 20000 | + | x | ) |
| ( | 42420 | + | 43 25 | x | ) | = | 9 5 | ( | 20000 | + | x | ) |
| 42420 | + | 43 25 | x | = | 9 5 | ( | 20000 | + | x | ) |
| 42420 | + | 43 25 | x | = | 9 5 | × | 20000 | + | 9 5 | x |
| 42420 | + | 43 25 | x | = | 36000 | + | 9 5 | x |
43 25 | x | − | 9 5 | x | = | 36000 | − | 42420 |
| - | 2 25 | x | = | 36000 | − | 42420 |
| - | 2 25 | x | = | - | 6420 |
| 6420 | = | 2 25 | x |
2 25 | x | = | 6420 |
| x | = | 6420 | ÷ | 2 25 |
| = | 6420 | × | 25 2 |
| = | 3210 | × | 25 |
| x | = | 80250 |