( | 1 | − | x | ) | ( | 5 | − | x | ) | ( | 9 | − | x | ) | = | 0 |
方程左边 = | 1 | ( | 5 | − | x | ) | ( | 9 | − | x | ) | − | x | ( | 5 | − | x | ) | ( | 9 | − | x | ) |
= | 1 | × | 5 | ( | 9 | − | x | ) | − | 1 | x | ( | 9 | − | x | ) | − | x | ( | 5 | − | x | ) | ( | 9 | − | x | ) |
= | 5 | ( | 9 | − | x | ) | − | 1 | x | ( | 9 | − | x | ) | − | x | ( | 5 | − | x | ) | ( | 9 | − | x | ) |
= | 5 | × | 9 | − | 5 | x | − | 1 | x | ( | 9 | − | x | ) | − | x | ( | 5 | − | x | ) | ( | 9 | − | x | ) |
= | 45 | − | 5 | x | − | 1 | x | ( | 9 | − | x | ) | − | x | ( | 5 | − | x | ) | ( | 9 | − | x | ) |
= | 45 | − | 5 | x | − | 1 | x | × | 9 | + | 1 | x | x | − | x | ( | 5 | − | x | ) | ( | 9 | − | x | ) |
= | 45 | − | 5 | x | − | 9 | x | + | 1 | x | x | − | x | ( | 5 | − | x | ) | ( | 9 | − | x | ) |
= | 45 | − | 14 | x | + | 1 | x | x | − | x | ( | 5 | − | x | ) | ( | 9 | − | x | ) |
= | 45 | − | 14 | x | + | 1 | x | x | − | x | × | 5 | ( | 9 | − | x | ) | + | x | x | ( | 9 | − | x | ) |
= | 45 | − | 14 | x | + | 1 | x | x | − | x | × | 5 | × | 9 | + | x | × | 5 | x |
= | 45 | − | 14 | x | + | 1 | x | x | − | x | × | 45 | + | x | × | 5 | x | + | x |
= | 45 | − | 59 | x | + | 1 | x | x | + | x | × | 5 | x | + | x | x | ( | 9 | − | x | ) |
= | 45 | − | 59 | x | + | 1 | x | x | + | x | × | 5 | x | + | x | x | × | 9 |
45 | − | 59 | x | + | 1 | x | x | + | x | × | 5 | x | + | x | x | × | 9 | = | 0 |