- | x | ( | 1 | − | x | ) | ( | - | 1 | − | x | ) | − | 2 | + | 8 | x | = | 0 |
方程左边 = | - | x | × | 1 | ( | - | 1 | − | x | ) | + | x | x | ( | - | 1 | − | x | ) | − | 2 | + | 8 | x |
= | x | × | 1 | × | 1 | + | x | × | 1 | x | + | x | x | ( | - | 1 | − | x | ) | − | 2 | + | 8 | x |
= | x | × | 1 | + | x | × | 1 | x | + | x | x | ( | - | 1 | − | x | ) | − | 2 | + | 8 | x |
= | 9 | x | + | x | × | 1 | x | + | x | x | ( | - | 1 | − | x | ) | − | 2 |
= | 9 | x | + | x | × | 1 | x | − | x | x | × | 1 | − | x | x | x | − | 2 |
9 | x | + | x | × | 1 | x | − | x | x | × | 1 | − | x | x | x | − | 2 | = | 0 |