1/1X3+1/3X5+…….+1/99X101
来源:百度知道 编辑:UC知道 时间:2024/06/16 20:37:46
1/1X3+1/3X5+…….+1/99X101
=1/2(1-1/3)+1/2(1/3-1/5)+…….+1/2(1/99-1/101)
=1/2(1-1/3+1/3-1/5+……+1/99-1/101)
=1/2(1-1/101)
=1/2*100/101
=50/101
=1/2(1-1/3+1/3-1/5+1/5-1/7....1/99-1/101)
=1/2(1-1/101)
=50/101
约分啊
最后为101
1/(1×3)+1/(3×5)+···+1/(99×101)
=(1-(1/3))/2+((1/3)-(1/5))/2+···+((1/99)-(1/101))/2
=(1-(1/3)+(1/3)-(1/5)+···+(1/99)-(1/101))/2
=(1-(1/101))/2
=50/101
=1/2(1-1/3+1/3-1/5+1/5-……-1/99+1/99-1/101)
=1/2(1-1/101)
=50/101
1-2/3+2/3-3/5+.......+50/99-51/101=1-51/101=50/101
答案是50/101
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