肥媽媽 2008-7-8 20:42
SOS.....数学盲求助数学题
计算： 111...1× 999...9
┖2002个┚ ┖2002个┚.
yeq16 2008-7-8 21:04
111......1× 999.,,,..9
┖2002个┚ ┖2002个┚
=111.......1× (100........0 - 1)
┖2002个┚ ┖2002个┚
=111.......100..........0-111.......1
┖2002个┚┖2002个┚ ┖2002个┚
=111........10888.......89
┖2001个┚ ┖2001个┚.
咪猫妈妈 2008-7-8 21:09
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[[i] 本帖最后由 yangjun6910 于 2008-7-8 21:10 编辑 [/i]].
肥媽媽 2008-7-8 21:13
[tt5] [em01] [em01] [em01] [em01].
ttony妈妈 2008-7-8 21:14
简单！！
有两种做法：
Number 1
1111...111(2002个）x［100...00（2002 个0）－1］
＝1111....1111(2002个）x1000...0000（2002 个0）－1111....1111(2002个）
= 111...1111(2002个）00.....0000(2002个）－1111....1111(2002个）
= 111.....11111(2001个1）0888....8888(2001个8）9
[tt8] [tt2]
Number 2
找规律：
99x11=1089
999x111=110889
9999x1111=11108889
.......
.........
...........
9999...9999(2002个）x1111....1111(2002个）
= 111.....11111(2001个1）0888....8888(2001个8）9
[tt4] [em03].
肥媽媽 2008-7-8 21:21
[em01] [em01] [em01] [em01] [em01] [em01] [em01]
[s:074.gif] :'(
太厉害了:'(.