| 1200 | ÷ | ( | 3 | x | ) | = | 2000 | ÷ | ( | 4 | x | ) | − | 2400 |
| 方程两边同时乘以: | ( | 3 | x | ) | , | ( | 4 | × | 1 | ) |
| 1200 | ( | 4 | × | 1 | ) | = | 2000 | ( | 3 | × | 1 | ) | − | 2400 | ( | 3 | x | ) | ( | 4 | × | 1 | ) |
| 1200 | × | 4 | × | 1 | = | 2000 | ( | 3 | × | 1 | ) | − | 2400 | ( | 3 | x | ) | ( | 4 | × | 1 | ) |
| 1200 | × | 4 | × | 1 | = | 2000 | × | 3 | × | 1 | − | 2400 | ( | 3 | x | ) | ( | 4 | × | 1 | ) |
| 4800 | = | 6000 | − | 2400 | ( | 3 | x | ) | ( | 4 | × | 1 | ) |
| 4800 | = | 6000 | − | 2400 | × | 3 | x | ( | 4 | × | 1 | ) |
| 4800 | = | 6000 | − | 7200 | x | ( | 4 | × | 1 | ) |
| 4800 | = | 6000 | − | 7200 | x | × | 4 | × | 1 |
| 4800 | = | 6000 | − | 28800 | x |
| 28800 | x | = | 6000 | − | 4800 |
| 28800 | x | = | 1200 |
| x | = | 1200 | ÷ | 28800 |
| = | 1200 | × | 1 28800 |
| = | 1 | × | 1 24 |
| x | = | 1 24 |
| x | = | 0.041667 |