1/1*3+1/3*5+1/5*7+...+1/95*97+1/97*99
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1/1*3+1/3*5+1/5*7+...+1/95*97+1/97*991/1*3+1/3*5+1/5*7+...+1/95*97+1/97*991/1*3+1/3*5+1/5*7+...+1/95
1/1*3+1/3*5+1/5*7+...+1/95*97+1/97*99
1/1*3+1/3*5+1/5*7+...+1/95*97+1/97*99
1/1*3+1/3*5+1/5*7+...+1/95*97+1/97*99
∵1/1*3=1/2*(1/1-1/3)
1/3*5=1/2*(1/3-1/5)
1/5*7=1/2*(1/5-1/7)
……
1/95*97=1/2*(1/95-1/97)
1/97*99=1/2*(1/97-1/99)
∴原式就=1/2*(1/1-1/3)+1/2*(1/3-1/5)+1/2*(1/5-1/7)+……+1/2*(1/95-1/97)+1/2*(1/97-1/99)
=1/2*(1/1-1/3+1/3-1/5+1/5-1/7+……+1/95-1/97+1/97-1/99)
=1/2*(1-1/99)
=1/2*(98/99)
=49/99
=0.5*(1/1-1/3)+0.5*(1/3-1/5)........=0.5*(1-1/99)
=49/99
1/1*3=0.5*(1/1-1/3)
化简得到
=0.5*(1-1/3+1/3-1/5...+1/97-1/99)
=49/99
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