✔ 最佳答案
Let (2003n + 2002) / (20n + 2) = m is an positive integer , then
n(20m - 2003) + 2m - 2002 = 0
n = (2002 - 2m) / (20m - 2003)
10n + 1
= [(20020 - 20m) + 20m - 2003] / (20m - 2003)
= 18017 / (20m - 2003)
= 43 x 419 / (20m - 2003) is an positive integer.
∴ 20m - 2003 = 43 (rejected) or 419 (rejected)
or 18017 ⇒ m = 1001
Hence n = (2002 - 2*1001) / (20*1001 - 2003) = 0 only.
2013-01-05 11:38:39 補充:
Note : 2003n + 2002 ≠ 0 so m is an positive integer.
2013-01-05 13:21:01 補充:
Missing 20m - 2003 = 1 (rejected)