1.一乘四分之一加四乘七分之一加七乘十分之一加十乘十三分之一加……加九十七乘一百分之一2.1*2*3/1+2*3*4/1+3*4*5/1+4*5*6/1+5*6*7/13.1*3/1+3*5/1+5*7/1+7*9/1+9*11/1+11*13/1+13*15/1
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/13 19:33:24
![1.一乘四分之一加四乘七分之一加七乘十分之一加十乘十三分之一加……加九十七乘一百分之一2.1*2*3/1+2*3*4/1+3*4*5/1+4*5*6/1+5*6*7/13.1*3/1+3*5/1+5*7/1+7*9/1+9*11/1+11*13/1+13*15/1](/uploads/image/z/217099-19-9.jpg?t=1.%E4%B8%80%E4%B9%98%E5%9B%9B%E5%88%86%E4%B9%8B%E4%B8%80%E5%8A%A0%E5%9B%9B%E4%B9%98%E4%B8%83%E5%88%86%E4%B9%8B%E4%B8%80%E5%8A%A0%E4%B8%83%E4%B9%98%E5%8D%81%E5%88%86%E4%B9%8B%E4%B8%80%E5%8A%A0%E5%8D%81%E4%B9%98%E5%8D%81%E4%B8%89%E5%88%86%E4%B9%8B%E4%B8%80%E5%8A%A0%E2%80%A6%E2%80%A6%E5%8A%A0%E4%B9%9D%E5%8D%81%E4%B8%83%E4%B9%98%E4%B8%80%E7%99%BE%E5%88%86%E4%B9%8B%E4%B8%802.1%2A2%2A3%2F1%2B2%2A3%2A4%2F1%2B3%2A4%2A5%2F1%2B4%2A5%2A6%2F1%2B5%2A6%2A7%2F13.1%2A3%2F1%2B3%2A5%2F1%2B5%2A7%2F1%2B7%2A9%2F1%2B9%2A11%2F1%2B11%2A13%2F1%2B13%2A15%2F1)
1.一乘四分之一加四乘七分之一加七乘十分之一加十乘十三分之一加……加九十七乘一百分之一2.1*2*3/1+2*3*4/1+3*4*5/1+4*5*6/1+5*6*7/13.1*3/1+3*5/1+5*7/1+7*9/1+9*11/1+11*13/1+13*15/1
1.一乘四分之一加四乘七分之一加七乘十分之一加十乘十三分之一加……加九十七乘一百分之一
2.1*2*3/1+2*3*4/1+3*4*5/1+4*5*6/1+5*6*7/1
3.1*3/1+3*5/1+5*7/1+7*9/1+9*11/1+11*13/1+13*15/1
1.一乘四分之一加四乘七分之一加七乘十分之一加十乘十三分之一加……加九十七乘一百分之一2.1*2*3/1+2*3*4/1+3*4*5/1+4*5*6/1+5*6*7/13.1*3/1+3*5/1+5*7/1+7*9/1+9*11/1+11*13/1+13*15/1
1、
=(1/3)*(1-1/4)+(1/3)*(1/4-1/7)+(1/3)*(1/7-1/10)+……+(1/3)*(1/97-1/100)
=(1/3)*(1-1/4+1/4-1/7+1/7-1/10+……+1/97-1/100)
=(1/3)*(1-1/100)
=33/10
2、
=1/2*(1/1*2-1/2*3)+1/2*(1/2*3-1/3*4)+1/2*(1/3*4-1/4*5)+1/2*(1/4*5-1/5*6)+1/2*(1/5*6-1/6*7)
=1/2*(1/1*2-1/6*7)
=5/21
3、
=1/2*(1-1/3)+1/2*(1/3-1/5)+……+1/2*(1/13-1/15)
=1/2*(1-1/3+1/3-1/5+……+1/13-1/15)
=1/2*(1-1/15)
=7/15
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