| ( | x | − | 40 | ) | ( | 150 | − | 5 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) | ) | = | 5600 |
| 方程左边 = | x | ( | 150 | − | 5 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) | ) | − | 40 | ( | 150 | − | 5 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) | ) |
| = | x | × | 150 | − | x | × | 5 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) | − | 40 | ( | 150 | − | 5 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) | ) |
| = | 150 | x | − | x | × | 5 | ( | x | − | 60 | ) | ÷ | 10 | − | 40 | ( | 150 | − | 5 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) | ) |
| = | 150 | x | − | x | × | 1 2 | ( | x | − | 60 | ) | − | 40 | ( | 150 | − | 5 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) | ) |
| = | 150 | x | − | x | × | 1 2 | x | + | x | × | 1 2 | × | 60 | − | 40 | ( | 150 | − | 5 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) | ) |
| = | 150 | x | − | x | × | 1 2 | x | + | x | × | 30 | − | 40 | ( | 150 | − | 5 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) | ) |
| = | 180 | x | − | x | × | 1 2 | x | − | 40 | ( | 150 | − | 5 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) | ) |
| = | 180 | x | − | x | × | 1 2 | x | − | 40 | × | 150 | + | 40 | × | 5 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) |
| = | 180 | x | − | x | × | 1 2 | x | − | 6000 | + | 200 | ( | ( | x | − | 60 | ) | ÷ | 10 | ) |
| = | 180 | x | − | x | × | 1 2 | x | − | 6000 | + | 200 | ( | x | − | 60 | ) | ÷ | 10 |
| = | 180 | x | − | x | × | 1 2 | x | − | 6000 | + | 20 | ( | x | − | 60 | ) |
| = | 180 | x | − | x | × | 1 2 | x | − | 6000 | + | 20 | x | − | 20 | × | 60 |
| = | 180 | x | − | x | × | 1 2 | x | − | 6000 | + | 20 | x | − | 1200 |
| = | 200 | x | − | x | × | 1 2 | x | − | 7200 |
| 200 | x | − | x | × | 1 2 | x | − | 7200 | = | 5600 |