1/2+3/4+5/6+7/8+9/10+11/12+13/14+15/16+17/18+19/20 值 求讲解
1/2+3/4+5/6+7/8+9/10+11/12+13/14+15/16+17/18+19/20
值
求讲解
1/2+3/4+5/6+7/8+9/10+11/12+13/14+15/16+17/18+19/20
=（1-1/2)+(1-1/4)+(1-1/6)+(1-1/8)......+(1-1/20)
=10-(1/2+1/4+1/8+1/10+1/12+1/14+1/16+1/18+1/20)
=10-(1/2+1/4+1/8++1/16+1/12+1/18+1/14+1/10+1/20)
=10-(155/144+31/140)
=10-(6541/5040)
=8又3539/5040
=（1-1/2)+(1-1/4)+(1-1/6)+(1-1/8)......+(1-1/20)
=10-(1/2+1/4+1/8+1/10+1/12+1/14+1/16+1/18+1/20)
=10-(1/2+1/4+1/8++1/16+1/12+1/18+1/14+1/10+1/20)
=10-(155/144+31/140)
=10-(6541/5040)
=8又3539/5040
温馨提示：内容为网友见解，仅供参考
第1个回答 2012-05-20
原式=（1-1/2)+(1-1/4)+(1-1/6)+......+(1-1/20) 接下去的就简单了追问
帮我算出来
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