1/1×3+1/3×5+1/5×7+...+1/99×101=?

来源：学生作业帮助网 编辑：作业帮 时间：2024/12/02 10:28:31
1/1×3+1/3×5+1/5×7+...+1/99×101=?
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1/1×3+1/3×5+1/5×7+...+1/99×101=?
1/1×3+1/3×5+1/5×7+...+1/99×101=?

1/1×3+1/3×5+1/5×7+...+1/99×101=?
好晕啊,看了半天看明白了,题目是：
1/（1×3）+1/（3×5）+1/（5×7）+...+1/（99×101）
拆项呀!
比如1/（1×3）=1/2*（1/1-1/3）
然后消掉中间N多项
得到：1/2（1-1/101）=50/101

1/1×3+1/3×5+1/5×7+...+1/99×101
=1/2(1-1/3+1/3-1/5+1/5-1/7+....+1/99-1/101)
=1/2(1-1/101)
=50/101

=1/2*(1-1/101)=1/2*100/101=100/202

1-3+5-7+... (1+1/3+1/5+1/7)*(1/3+1/5+1/7+1/9)-(1+1/3+1/5+1/7+1/9)*(1/3+1/5+1/7) 简算(1+1/3+1/5+1/7)*(1/3+1/5+1/7+1/9)-(1+1/3+1/5+1/7+1/9)*(1/3+1/5+1/7) 简便计算 1/1*3+1/1*3*5+1/1*3*5*7+1/1*3*5*7*9-73/945 (1/3+1/5+1/7)*(1/5+1/7+1/9)-(1/3+1/5+1/7+1/9)*(1/5+1/7)=? 1/3+1/5+1/7+.+1/2n+1 1/1*3*5+1/3*5*7+1/5*7*9.+1/95*97*99 1/1×3+1/3×5+1/5×7+1/7×9.+1/2011×2013 简算:1/1*3+1/3*5+1/5*7+1/7*9+1/9*11 1/1*3+1/3*5+1/5*7+1/7*9+...1/17*19= 计算1/(1×3)+1/(3×5)+1/(5×7)+1/(7×9)+.+1/(19×21) 1/1×3+1/3×5+1/5×7+1/7×9+.+1/2013×2015 1/1*3+1/3*5+1/5*7+1/7*9+.+1/101*103 帮帮忙1/1*3+1/3*5+1/5*7+1/7*9+...1/99*101 1/1*3+1/3*5+1/5*7+1/7*9+1/49*51= 计算：1/1×3+1/3×5+1/5×7+1/7×9``````+1/2001×2003 (1*3)/1+(3*5)/1+(5*7)/1+(7*9)/1+(9*11)/1 1/1*3+1/3*5+1/5*7+1/7*9+1/9*11 (1*3)/1+(3*5)/1+(5*7)/1+(7*9)/1+(9*11)/1