(1/8+1/24+1/48+1/80+1/120+1/168+1/224+1/228)*128

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(1/8+1/24+1/48+1/80+1/120+1/168+1/224+1/228)*128
(1/8+1/24+1/48+1/80+1/120+1/168+1/224+1/228)*128

(1/8+1/24+1/48+1/80+1/120+1/168+1/224+1/228)*128
(1/8+1/24+1/48+1/80+1/120+1/168+1/224+1/288)*128
=(1/2+1/6+1/12+1/20+1/30+1/42+14/56+1/72)*32
=(1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9)*32
=(1-1/9)*32
=8/9*32
=256/9

=(1/2-1/4+1/4-1/6+1/6-1/8+1/8-1/10+1/10-1/12+1/12-1/14+1/14-1/16+1/16-1/18)*128
=(1/2-1/18)*128
=(8/18)*128
=4*128/9
=512/9请问是什么思路方便讲一下 还有个题麻烦你:2005个9*2005个9+1 2005个9这个不是靠思路,是靠经验,你...

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=(1/2-1/4+1/4-1/6+1/6-1/8+1/8-1/10+1/10-1/12+1/12-1/14+1/14-1/16+1/16-1/18)*128
=(1/2-1/18)*128
=(8/18)*128
=4*128/9
=512/9

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