| ( | - | 2 | a | + | 100 | ) | ( | a | − | 34 | ) | = | 150 |
| 方程左边 = | - | 2 | a | ( | a | − | 34 | ) | + | 100 | ( | a | − | 34 | ) |
| = | - | 2 | a | a | + | 2 | a | × | 34 | + | 100 | ( | a | − | 34 | ) |
| = | - | 2 | a | a | + | 68 | a | + | 100 | ( | a | − | 34 | ) |
| = | - | 2 | a | a | + | 68 | a | + | 100 | a | − | 100 | × | 34 |
| = | - | 2 | a | a | + | 68 | a | + | 100 | a | − | 3400 |
| = | - | 2 | a | a | + | 168 | a | − | 3400 |
| - | 2 | a | a | + | 168 | a | − | 3400 | = | 150 |