1/1* 3+1/3* 5+1/5 7+ ... +1/2007 2009,要有理由

来源：学生作业帮助网编辑：作业帮时间：2024/05/06 00:38:21

1/1* 3+1/3* 5+1/5 *7+ ... +1/2007* 2009,要有理由
1/1* 3+1/3* 5+1/5 *7+ ... +1/2007* 2009,要有理由

1/1* 3+1/3* 5+1/5 *7+ ... +1/2007* 2009,要有理由
=1/2*(1-1/3+1/3-1/5+1/5-1/7+……++1/2007-1/2009)
=1/2*(1-1/2009)
=1004/2009

1/1* 3+1/3* 5+1/5 *7+ ... +1/2007* 2009
=（1/2)(1-1/3)+(1/2)(1/3-1/5)+(1/2)(1/5-1/7)+.......+(1/2)(1/2007-1/2009)
=(1/2)(1-1/3+1/3-1/5+1/5-1/7+.....+1/2005-1/2007+1/2007-1/2009)
=(1/2)(1-1/2009)=1004/2009

收起

=1/2[1-1/3十1/3-1/5十.....十1/200|-1/2009]=1/2[1-1/2009]=1004/2009

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