| ( | 50 | × | 3 | × | 60 | ) | ÷ | ( | 60 | − | 50 | ) | = | x |
| 方程两边同时乘以: | ( | 60 | − | 50 | ) |
| ( | 50 | × | 3 | × | 60 | ) | = | x | ( | 60 | − | 50 | ) |
| 50 | × | 3 | × | 60 | = | x | ( | 60 | − | 50 | ) |
| 50 | × | 3 | × | 60 | = | x | × | 60 | − | x | × | 50 |
| 9000 | = | x | × | 60 | − | x | × | 50 |
| 9000 | = | 10 | x |
| - | 10 | x | = | - | 9000 |
| 9000 | = | 10 | x |
| 10 | x | = | 9000 |
| x | = | 9000 | ÷ | 10 |
| = | 9000 | × | 1 10 |
| = | 900 | × | 1 |
| x | = | 900 |