| 2 | x | ( | 1 | + | x | ) | x | ( | 1 | + | x | ) | = | 19 2 |
| 方程左边 = | 2 | x | × | 1 | x | ( | 1 | + | x | ) | + | 2 | x | x | x | ( | 1 | + | x | ) |
| = | 2 | x | x | ( | 1 | + | x | ) | + | 2 | x | x | x | ( | 1 | + | x | ) |
| = | 2 | x | x | × | 1 | + | 2 | x | x | x | + | 2 | x | x | x |
| = | 2 | x | x | + | 2 | x | x | x | + | 2 | x | x | x | ( | 1 | + | x | ) |
| = | 2 | x | x | + | 2 | x | x | x | + | 2 | x | x | x | × | 1 |
| = | 2 | x | x | + | 2 | x | x | x | + | 2 | x | x | x | + | 2 |
| 2 | x | x | + | 2 | x | x | x | + | 2 | x | x | x | + | 2 | = | 19 2 |