| 4320 | ÷ | x | = | 2 | ( | 3060 | ÷ | ( | x | + | 50 | ) | ) |
| 方程两边同时乘以: | x |
| 4320 | = | 2 | ( | 3060 | ÷ | ( | x | + | 50 | ) | ) | x |
| 4320 | = | 2 | × | 3060 | ÷ | ( | x | + | 50 | ) | × | x |
| 4320 | = | 6120 | ÷ | ( | x | + | 50 | ) | × | x |
| 方程两边同时乘以: | ( | x | + | 50 | ) |
| 4320 | ( | x | + | 50 | ) | = | 6120 | x |
| 4320 | x | + | 4320 | × | 50 | = | 6120 | x |
| 4320 | x | + | 216000 | = | 6120 | x |
| 4320 | x | − | 6120 | x | = | - | 216000 |
| - | 1800 | x | = | - | 216000 |
| 216000 | = | 1800 | x |
| 1800 | x | = | 216000 |
| x | = | 216000 | ÷ | 1800 |
| = | 216000 | × | 1 1800 |
| = | 120 | × | 1 |
| x | = | 120 |