1/1*3+1/3*5+1/5*7+...+1/17*19

来源：学生作业帮助网 编辑：六六作业网 时间：2024/05/03 20:26:49
1/1*3+1/3*5+1/5*7+...+1/17*191/1*3+1/3*5+1/5*7+...+1/17*191/1*3+1/3*5+1/5*7+...+1/17*191/1*3+1/3*5+1

1/1*3+1/3*5+1/5*7+...+1/17*19
1/1*3+1/3*5+1/5*7+...+1/17*19

1/1*3+1/3*5+1/5*7+...+1/17*19
1/1*3+1/3*5+1/5*7+...+1/17*19
=1/2 x (1/1 -1/3 +1/3 -1/5 +...+1/17 -1/19)
=1/2 x (1 - 1/19)
=9/19

1/1*3+1/3*5+1/5*7+...+1/17*19
=（1-1/3+1/3-1/5+1/5-1/7+……+1/17-1/19）÷2
=（1-1/19）÷2
=18/19÷2
=9/19

上式可化为（1-2/3）+（2/3-3/5）+（3/5-4/7）+...+（9/17-10/19）=1-10/19=9/19
分子分别为：1 2 2 3 3 4....
分母分别为：1 3 3 5 3 7...

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