10 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | = | 121 10 |
方程左边 = | 10 | × | 1 | ( | 1 | + | x | ) | + | 10 | x | ( | 1 | + | x | ) |
= | 10 | ( | 1 | + | x | ) | + | 10 | x | ( | 1 | + | x | ) |
= | 10 | × | 1 | + | 10 | x | + | 10 | x | ( | 1 | + | x | ) |
= | 10 | + | 10 | x | + | 10 | x | ( | 1 | + | x | ) |
= | 10 | + | 10 | x | + | 10 | x | × | 1 | + | 10 | x | x |
= | 10 | + | 10 | x | + | 10 | x | + | 10 | x | x |
= | 10 | + | 20 | x | + | 10 | x | x |
10 | + | 20 | x | + | 10 | x | x | = | 121 10 |
x1= | - | 21 10 |
x2= | 1 10 |