( | x | − | 3 | ) | ( | x | + | 2 | ) | ( | x | + | 1 | ) | = | 0 |
方程左边 = | x | ( | x | + | 2 | ) | ( | x | + | 1 | ) | − | 3 | ( | x | + | 2 | ) | ( | x | + | 1 | ) |
= | x | x | ( | x | + | 1 | ) | + | x | × | 2 | ( | x | + | 1 | ) | − | 3 | ( | x | + | 2 | ) | ( | x | + | 1 | ) |
= | x | x | x | + | x | x | × | 1 | + | x | × | 2 | ( | x | + | 1 | ) | − | 3 | ( | x | + | 2 | ) | ( | x | + | 1 | ) |
= | x | x | x | + | x | x | × | 1 | + | x | × | 2 | x | + | x | × | 2 | × | 1 |
= | x | x | x | + | x | x | × | 1 | + | x | × | 2 | x | + | x | × | 2 | − | 3 |
= | x | x | x | + | x | x | × | 1 | + | x | × | 2 | x | + | 2 | x | − | 3 |
= | x | x | x | + | x | x | × | 1 | + | x | × | 2 | x | + | 2 | x | − | 3 |
= | x | x | x | + | x | x | × | 1 | + | x | × | 2 | x | + | 2 | x | − | 3 |
= | x | x | x | + | x | x | × | 1 | + | x | × | 2 | x | + | 2 | x | − | 3 |
= | x | x | x | + | x | x | × | 1 | + | x | × | 2 | x | − | 1 | x | − | 3 |
= | x | x | x | + | x | x | × | 1 | + | x | × | 2 | x | − | 1 | x | − | 3 |
= | x | x | x | + | x | x | × | 1 | + | x | × | 2 | x | − | 1 | x | − | 3 |
= | x | x | x | + | x | x | × | 1 | + | x | × | 2 | x | − | 7 | x | − | 3 |
x | x | x | + | x | x | × | 1 | + | x | × | 2 | x | − | 7 | x | − | 3 | = | 0 |