用简便算法1/2+5/6+11/12+19/20+29/30+...+9701/9702+9899/9900=?
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用简便算法1/2+5/6+11/12+19/20+29/30+...+9701/9702+9899/9900=?
用简便算法
1/2+5/6+11/12+19/20+29/30+...+9701/9702+9899/9900=?
用简便算法1/2+5/6+11/12+19/20+29/30+...+9701/9702+9899/9900=?
1/2+5/6+11/12+19/20+29/30+9701/9702+9899/9900
=1/2+(1/2+1/3+(2/3+1/4)+(3/4+1/5)+(4/5+1/6)…… + (97/98+1/99)+(98/99 +1/100)
=(1/2+1/2)+(1/3+2/3)+(1/4+3/4)……(98/99+1/99)+1/100
=1+1+1+1+……+1/100 其中有98个1
=98+1/100
=9801/100
1/2+5/6+11/12+19/20+29/30+...+9701/9702+9899/9900
=1/2+(1-1/6)+(1-1/12)+(1-1/20)+(1-1/30)+……+(1-1/9702)+
=1/2+[1-(1/2-1/3)]+[1-(1/3-1/4)]+[1-(1/4-1/5)]+[1-(1/5-1/6)]+……+[1-(1/98-1/99)]+[1-(1...
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1/2+5/6+11/12+19/20+29/30+...+9701/9702+9899/9900
=1/2+(1-1/6)+(1-1/12)+(1-1/20)+(1-1/30)+……+(1-1/9702)+
=1/2+[1-(1/2-1/3)]+[1-(1/3-1/4)]+[1-(1/4-1/5)]+[1-(1/5-1/6)]+……+[1-(1/98-1/99)]+[1-(1/99-1/100)]
=1*100+1/2-1/2+1/3-1/3+1/4-1/4+1/5-1/5+1/6-1/6+……1/98-1/98+1/99-1/99+1/100
=100+1/100
收起
1/2+5/6+11/12+19/20+29/30+...+9701/9702+9899/9900
=1/2+(1-1/6)+(1-1/12)+(1-1/20)+(1-1/30)+……+(1-1/9702)+(1-1/9900)
=1/2+[1-(1/2-1/3)]+[1-(1/3-1/4)]+[1-(1/4-1/5)]+[1-(1/5-1/6)]+……+[1-(1/98-1/...
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1/2+5/6+11/12+19/20+29/30+...+9701/9702+9899/9900
=1/2+(1-1/6)+(1-1/12)+(1-1/20)+(1-1/30)+……+(1-1/9702)+(1-1/9900)
=1/2+[1-(1/2-1/3)]+[1-(1/3-1/4)]+[1-(1/4-1/5)]+[1-(1/5-1/6)]+……+[1-(1/98-1/99)]+[1-(1/99-1/100)]
=1*100+1/2-1/2+1/3-1/3+1/4-1/4+1/5-1/5+1/6-1/6+……1/98-1/98+1/99-1/99+1/100
=100+1/100
=100又1/100
收起