| ( | 50 | + | 100 | x | ) | ( | 1 | + | x | ÷ | 2 | ) | = | 0 |
| 方程左边 = | 50 | ( | 1 | + | x | ÷ | 2 | ) | + | 100 | x | ( | 1 | + | x | ÷ | 2 | ) |
| = | 50 | × | 1 | + | 50 | x | ÷ | 2 | + | 100 | x | ( | 1 | + | x | ÷ | 2 | ) |
| = | 50 | + | 25 | x | + | 100 | x | ( | 1 | + | x | ÷ | 2 | ) |
| = | 50 | + | 25 | x | + | 100 | x | × | 1 | + | 100 | x | x | ÷ | 2 |
| = | 50 | + | 25 | x | + | 100 | x | + | 50 | x | x |
| = | 50 | + | 125 | x | + | 50 | x | x |
| 50 | + | 125 | x | + | 50 | x | x | = | 0 |
| x2= | - | 1 2 |