| ( | 3 | x | + | 4 | ) | ( | 3 | x | − | 4 | ) | − | ( | 2 | x | + | 3 | ) | ( | 3 | x | − | 2 | ) | = | 0 |
| 方程左边 = | 3 | x | ( | 3 | x | − | 4 | ) | + | 4 | ( | 3 | x | − | 4 | ) | − | ( | 2 | x | + | 3 | ) | ( | 3 | x | − | 2 | ) |
| = | 3 | x | × | 3 | x | − | 3 | x | × | 4 | + | 4 | ( | 3 | x | − | 4 | ) | − | ( | 2 | x | + | 3 | ) | ( | 3 | x | − | 2 | ) |
| = | 9 | x | x | − | 12 | x | + | 4 | ( | 3 | x | − | 4 | ) | − | ( | 2 | x | + | 3 | ) | ( | 3 | x | − | 2 | ) |
| = | 9 | x | x | − | 12 | x | + | 4 | × | 3 | x | − | 4 | × | 4 | − | ( | 2 | x | + | 3 | ) | ( | 3 | x | − | 2 | ) |
| = | 9 | x | x | − | 12 | x | + | 12 | x | − | 16 | − | ( | 2 | x | + | 3 | ) | ( | 3 | x | − | 2 | ) |
| = | 9 | x | x | − | 0 | x | − | 16 | − | ( | 2 | x | + | 3 | ) | ( | 3 | x | − | 2 | ) |
| = | 9 | x | x | − | 16 | − | 2 | x | ( | 3 | x | − | 2 | ) | − | 3 | ( | 3 | x | − | 2 | ) |
| = | 9 | x | x | − | 16 | − | 2 | x | × | 3 | x | + | 2 | x | × | 2 | − | 3 |
| = | 9 | x | x | − | 16 | − | 6 | x | x | + | 4 | x | − | 3 | ( | 3 | x | − | 2 | ) |
| = | 9 | x | x | − | 16 | − | 6 | x | x | + | 4 | x | − | 3 | × | 3 | x |
| = | 9 | x | x | − | 16 | − | 6 | x | x | + | 4 | x | − | 9 | x | + | 6 |
| = | 9 | x | x | − | 10 | − | 6 | x | x | − | 5 | x |
| 9 | x | x | − | 10 | − | 6 | x | x | − | 5 | x | = | 0 |