| ( | 1500 | − | 100 | − | x | ) | ( | 50 | + | x | ÷ | 4 | ) | = | 0 |
| 方程左边 = | 1500 | ( | 50 | + | x | ÷ | 4 | ) | − | 100 | ( | 50 | + | x | ÷ | 4 | ) | − | x | ( | 50 | + | x | ÷ | 4 | ) |
| = | 1500 | × | 50 | + | 1500 | x | ÷ | 4 | − | 100 | ( | 50 | + | x | ÷ | 4 | ) | − | x | ( | 50 | + | x | ÷ | 4 | ) |
| = | 75000 | + | 375 | x | − | 100 | ( | 50 | + | x | ÷ | 4 | ) | − | x | ( | 50 | + | x | ÷ | 4 | ) |
| = | 75000 | + | 375 | x | − | 100 | × | 50 | − | 100 | x | ÷ | 4 | − | x | ( | 50 | + | x | ÷ | 4 | ) |
| = | 75000 | + | 375 | x | − | 5000 | − | 25 | x | − | x | ( | 50 | + | x | ÷ | 4 | ) |
| = | 70000 | + | 350 | x | − | x | ( | 50 | + | x | ÷ | 4 | ) |
| = | 70000 | + | 350 | x | − | x | × | 50 | − | x | x | ÷ | 4 |
| = | 70000 | + | 300 | x | − | x | x | × | 1 4 |
| 70000 | + | 300 | x | − | x | x | × | 1 4 | = | 0 |