(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

来源：学生作业帮编辑：搜搜做题作业网作业帮分类：数学作业时间：2024/07/30 02:48:35

(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

设1/3+1/5+1/7=x
进行替换
原式
=(1+x)(x+1/9)-(1+x+1/9)x
=x+1/9+x²+1/9x-x-x²-1/9x
=(x-x)+1/9+(x²-x²)+(1/9x-1/9x)
=0+1/9+0+0
=1/9
再问：你可以把 1+1/3+1/5+1/7设为A，把1/3+1/5+1/7设为B 来计算么？？请把过程写出来，O(∩_∩)O谢谢。
再答： 1+1/3+1/5+1/7设为A，把1/3+1/5+1/7设为B 原式 =A(B+1/9)-(A+1/9)B =AB+1/9A-AB-1/9B =(AB-AB)+1/9(A-B) =0+1/9 =1/9 如果你认可我的回答，请点击左下角的“采纳为满意答案”，祝学习进步！

(1/3+1/5+1/7+1/9)*(1/5+1/7+1/9+1/11)-(1/3+1/11+1/5+1/7+1/9)* (1/3+1/5+1/7)*(1/5+1/7+1/9)-(1/3+1/5+1/7+1/9)*(1/5+1/7)=? 简算:1/1*3+1/3*5+1/5*7+1/7*9+1/9*11 求数列1*(1/3)+(1/3)*(1/5)+(1/5)*(1/7)+(1/7)*(1/9)+...+(1/99)*(1 1/1*3+1/3*5+1/5*7+1/7*9+...1/17*19= 帮帮忙1/1*3+1/3*5+1/5*7+1/7*9+...1/99*101 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-^-1/19*21 1/1×3+1/3×5+1/5×7+1/7×9+.+1/2013×2015 计算：1/1×3+1/3×5+1/5×7+1/7×9``````+1/2001×2003 1/1*3+1/3*5+1/5*7+1/7*9+.+1/101*103 1+1+3+5+7+9