1/3+1/3*5+1/5*7+.+1/19*21=1-1/3+1/3-1/5+1/5+.-1/21=1-1/21=20/211是怎么来的?
来源：学生作业帮助网 编辑：六六作业网 时间：2024/11/17 00:52:10
1/3+1/3*5+1/5*7+.+1/19*21=1-1/3+1/3-1/5+1/5+.-1/21=1-1/21=20/211是怎么来的?1/3+1/3*5+1/5*7+.+1/19*21=1-1/
1/3+1/3*5+1/5*7+.+1/19*21=1-1/3+1/3-1/5+1/5+.-1/21=1-1/21=20/211是怎么来的?
1/3+1/3*5+1/5*7+.+1/19*21
=1-1/3+1/3-1/5+1/5+.-1/21
=1-1/21
=20/21
1是怎么来的?
1/3+1/3*5+1/5*7+.+1/19*21=1-1/3+1/3-1/5+1/5+.-1/21=1-1/21=20/211是怎么来的?
1/3+1/3*5+1/5*7+.+1/19*21
=1/2*(1-1/3+1/3-1/5+1/5+.-1/21)
=1/2*(1-1/21)
=10/21
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