1减3又6分之1减5又12分之1减7又20分之1减9又30分之1减11又42分之1减13又56分之1减15又72分之1减17又90分之1
=(1-3-5-7-9-11-13-15-17)-(1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90)
=(-79)-(1/4+1/20+1/30+1/42+1/56+1/72+1/90)
=(-79)-(3/10+1/30+1/42+1/56+1/72+1/90)
=(-79)-(1/3+1/42+1/56+1/72+1/90)
=(-79)-(5/14+1/56+1/72+1/90)
=(-79)-(21/56+1/72+1/90)
=(-79)-(49/126+1/90)
=(-79)-(49/126+1/90)
=(-79)-(4/5)
= - 79又5分之4
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024