| 100 | x | ÷ | ( | 200 | ( | 200 | − | x | ) | ) | = | 3 | ÷ | 4 |
| 方程两边同时乘以: | ( | 200 | ( | 200 | − | x | ) | ) |
| 100 | x | = | 3 | ÷ | 4 | × | ( | 200 | ( | 200 | − | x | ) | ) |
| 100 | x | = | 3 | ÷ | 4 | × | 200 | ( | 200 | − | x | ) |
| 100 | x | = | 150 | ( | 200 | − | x | ) |
| 100 | x | = | 150 | × | 200 | − | 150 | x |
| 100 | x | = | 30000 | − | 150 | x |
| 100 | x | + | 150 | x | = | 30000 |
| 250 | x | = | 30000 |
| x | = | 30000 | ÷ | 250 |
| = | 30000 | × | 1 250 |
| = | 120 | × | 1 |
| x | = | 120 |