2+2^2+2^3+...+ 2^k = 2^K+1 - 2
L.H.S
= 2+2^2+2^3...+2^k+2^k+1
=2^k+1 - 2 + 2^k+1
=2^k-2 - 2
點解會變左2^k-2 o既?!
更新1:
咁點解2^k+1 + 2^k+1 會等於 2^k+2???
咁點解2^k+1 + 2^k+1 會等於 2^k+2???
收錄日期: 2021-04-18 20:32:09
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20061226000051KK01962