| ( | 1 | − | x | ) | ( | 200 | + | 40 | x | ) | − | 24 | = | 200 |
| 方程左边 = | 1 | ( | 200 | + | 40 | x | ) | − | x | ( | 200 | + | 40 | x | ) | − | 24 |
| = | 1 | × | 200 | + | 1 | × | 40 | x | − | x | ( | 200 | + | 40 | x | ) | − | 24 |
| = | 200 | + | 40 | x | − | x | ( | 200 | + | 40 | x | ) | − | 24 |
| = | 176 | + | 40 | x | − | x | ( | 200 | + | 40 | x | ) |
| = | 176 | + | 40 | x | − | x | × | 200 | − | x | × | 40 | x |
| = | 176 | − | 160 | x | − | x | × | 40 | x |
| 176 | − | 160 | x | − | x | × | 40 | x | = | 200 |