( | X | + | 3 | ) | ( | X | − | 4 | ) | − | ( | X | − | 1 | ) | = | 0 |
方程左边 = | X | ( | X | − | 4 | ) | + | 3 | ( | X | − | 4 | ) | − | ( | X | − | 1 | ) |
= | X | X | − | X | × | 4 | + | 3 | ( | X | − | 4 | ) | − | ( | X | − | 1 | ) |
= | X | X | − | 4 | X | + | 3 | X | − | 3 | × | 4 | − | ( | X | − | 1 | ) |
= | X | X | − | 4 | X | + | 3 | X | − | 12 | − | ( | X | − | 1 | ) |
= | X | X | − | 1 | X | − | 12 | − | ( | X | − | 1 | ) |
= | X | X | − | 1 | X | − | 12 | − | X | + | 1 |
= | X | X | − | 2 | X | − | 11 |
X | X | − | 2 | X | − | 11 | = | 0 |