| ( | 6 | x | − | 48 | ) | ( | 3 | x | + | 3 | ) | = | 6 |
| 方程左边 = | 6 | x | ( | 3 | x | + | 3 | ) | − | 48 | ( | 3 | x | + | 3 | ) |
| = | 6 | x | × | 3 | x | + | 6 | x | × | 3 | − | 48 | ( | 3 | x | + | 3 | ) |
| = | 18 | x | x | + | 18 | x | − | 48 | ( | 3 | x | + | 3 | ) |
| = | 18 | x | x | + | 18 | x | − | 48 | × | 3 | x | − | 48 | × | 3 |
| = | 18 | x | x | + | 18 | x | − | 144 | x | − | 144 |
| = | 18 | x | x | − | 126 | x | − | 144 |
| 18 | x | x | − | 126 | x | − | 144 | = | 6 |