| 900 | ÷ | ( | 1 | − | 1 | ÷ | 4 | ) | × | x | − | 900 | ÷ | x | = | 200 |
| 方程两边同时乘以: | ( | 1 | − | 1 | ÷ | 4 | ) |
| 900 | x | − | 900 | ÷ | x | × | ( | 1 | − | 1 | ÷ | 4 | ) | = | 200 | ( | 1 | − | 1 | ÷ | 4 | ) |
| 900 | x | − | 900 | ÷ | x | × | 1 | + | 900 | ÷ | x | × | 1 | ÷ | 4 | = | 200 | ( | 1 | − | 1 | ÷ | 4 | ) |
| 900 | x | − | 900 | ÷ | x | × | 1 | + | 900 | ÷ | x | × | 1 | ÷ | 4 | = | 200 | × | 1 | − | 200 | × | 1 | ÷ | 4 |
| 900 | x | − | 900 | ÷ | x | + | 225 | ÷ | x | = | 200 | − | 50 |
| 900 | x | − | 900 | ÷ | x | + | 225 | ÷ | x | = | 150 |
| 方程两边同时乘以: | x |
| 900 | x | x | − | 900 | + | 225 | ÷ | 1 | × | 1 | = | 150 | x |