( | 70 | + | x | ) | ( | 10 | x | + | 7 | ) | + | x | x | x | x | x | x | = | 2008 |
方程左边 = | 70 | ( | 10 | x | + | 7 | ) | + | x | ( | 10 | x | + | 7 | ) | + | x | x | x | x | x | x |
= | 70 | × | 10 | x | + | 70 | × | 7 | + | x | ( | 10 | x | + | 7 | ) | + | x | x | x | x | x |
= | 700 | x | + | 490 | + | x | ( | 10 | x | + | 7 | ) | + | x | x | x | x | x | x |
= | 700 | x | + | 490 | + | x | × | 10 | x | + | x | × | 7 | + | x | x | x | x |
= | 707 | x | + | 490 | + | x | × | 10 | x | + | x | x | x | x | x | x |
707 | x | + | 490 | + | x | × | 10 | x | + | x | x | x | x | x | x | = | 2008 |
x1=2 |