( | x | − | 2 | ) | ( | x | + | 1 | ) | ( | x | + | 4 | ) | ( | x | + | 7 | ) | = | 19 |
方程左边 = | x | ( | x | + | 1 | ) | ( | x | + | 4 | ) | ( | x | + | 7 | ) | − | 2 | ( | x | + | 1 | ) | ( | x | + | 4 | ) | ( | x | + | 7 | ) |
= | x | x | ( | x | + | 4 | ) | ( | x | + | 7 | ) | + | x | × | 1 | ( | x | + | 4 | ) | ( | x | + | 7 | ) | − | 2 | ( | x | + | 1 | ) | ( | x | + | 4 | ) | ( | x | + | 7 | ) |
= | x | x | x | ( | x | + | 7 | ) | + | x | x | × | 4 | ( | x | + | 7 | ) | + | x | × | 1 | ( | x | + | 4 | ) | ( | x | + | 7 | ) |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | ( | x | + | 7 | ) |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |
= | x | x | x | x | + | x | x | x | × | 7 | + | x | x | × | 4 | x |