1 | − | 3 | a | ( | 1 | − | a | ( | 1 | − | 3 | a | ) | ) | = | 1 | − | 3 | a | ( | 1 | − | a | ) |
方程左边 = | 1 | − | 3 | a | × | 1 | + | 3 | a | a | ( | 1 | − | 3 | a | ) |
= | 1 | − | 3 | a | + | 3 | a | a | ( | 1 | − | 3 | a | ) |
= | 1 | − | 3 | a | + | 3 | a | a | × | 1 | − | 3 | a | a | × | 3 | a |
= | 1 | − | 3 | a | + | 3 | a | a | − | 9 | a | a | a |
1 | − | 3 | a | + | 3 | a | a | − | 9 | a | a | a | = | 1 | − | 3 | a | ( | 1 | − | a | ) |
方程右边 = | 1 | − | 3 | a | × | 1 | + | 3 | a | a |
= | 1 | − | 3 | a | + | 3 | a | a |
1 | − | 3 | a | + | 3 | a | a | − | 9 | a | a | a | = | 1 | − | 3 | a | + | 3 | a | a |