1 1 1 1 1 1 ____ + _____ + -------- + -------- + --------- + ----------- 1乘3乘5 3乘5乘7 5乘7乘9 71 1 1 1 1 1____ + _____ + -------- +

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1 1 1 1 1 1 ____ + _____ + -------- + -------- + --------- + ----------- 1乘3乘5 3乘5乘7 5乘7乘9 71                  1                        1                  1                 1                 1____      +     _____         +   --------  +

1 1 1 1 1 1 ____ + _____ + -------- + -------- + --------- + ----------- 1乘3乘5 3乘5乘7 5乘7乘9 71 1 1 1 1 1____ + _____ + -------- +
1 1 1 1 1 1 ____ + _____ + -------- + -------- + --------- + ----------- 1乘3乘5 3乘5乘7 5乘7乘9 7
1 1 1 1 1 1
____ + _____ + -------- + -------- + --------- + -----------
1乘3乘5 3乘5乘7 5乘7乘9 7乘9乘11 9乘11乘13 11乘13乘15

1 1 1 1 1 1 ____ + _____ + -------- + -------- + --------- + ----------- 1乘3乘5 3乘5乘7 5乘7乘9 71 1 1 1 1 1____ + _____ + -------- +
1/(1×3×5)=1/4×[1/(1×3)-1/(3×5)]
1/(3×5×7)=1/4×[1/(3×5)-1/(5×7)]
1/(5×7×9)=1/4×[1/(5×7)-1/(7×9)]
1/(7×9×11)=1/4×[1/(7×9)-1/(9×11)]
1/(9×11×13)=1/4×[1/(9×11)-1/(11×13)]
1/(11×13×15)=1/4×[1/(11×13)-1/(13×15)]
提取公因式1/4,然后相互抵消,得原式=1/4×[1/(1×3)-1/(13×15)]=1/4×64/195=16/195

数独计算_ _ 9 7 _ _ _ _ _2 _ _ _ _ _ _ 9 __ _ 1 5 _ _ _ _ 4_ 3 _ _ 1 _ 4 _ _1 _ _ 9 _ _ _ _ 8_ _ 2 _ _ _ _ 3 _6 _ _ _ _ 3 5 _ __ 5 _ _ _ _ _ _ 7_ _ _ _ _ 5 2 _ _ 81宫格填数字游戏_ _ _ _ _ 8 _ _ _8 _ 1 _ 5 _ 6 3 4_ 5 _ 3 6 4 _ _ __ _ _ _ 3 _ 9 _ 8_ _ _ 8 9 6 4 1 __ _ 5 _ _ _ _ _ 3_ _ _ _ _ _ _ _ __ _ _ _ _ 1 7 _ _7 _ 8 _ _ _ 1 _ _ 英语一些简单的题.1.写出与所给单词的划线字母含有相同读音的单词.(1)much _ _ _ _ _(2)nom _ _ _ _ _(3)slsire _ _ _ _ _(4)plcre _ _ _ _ _(5)else _ _ _ _ _(6)there _ _ _ _ _(7)sweet _ _ _ _ _(8)drink _ _ _ _ _(9)nice _ _ _ _ _( M_ _ _ _ 1 T _ _ 6 _ 2 _ W_ _ _ _ _ _ _ T _ 5 _ _ _ _ _ F _ _ 3 _ _ S _ _ _ _ _ _ _ _ S _ 4 _ _ _My favorite day is __ __ __ __ __ __6 5 4 3 2 1 天空组词语 1 _ _ _ _ 1 _ _ _ _1 _ _ _ _1 例:漓江的水真绿啊,绿得仿佛那是一块无瑕的翡翠.1、这桂花真香啊,香得_ _ _ _ _ _ _ _ _ _ _ _ _ _ 例:漓江的水真绿啊,绿得仿佛那是一块无瑕的翡翠.1、这桂花真香啊,香得_ _ _ _ _ _ _ _ _ _ _ _ _ _ 一道数学序列题1 1 2 1 2 3 1 2 3 4 1 2_,_,_,_,_,_,_,_,_,_,_,_,+... 数列填空1到九填空!6 _ _ 9 _ _ - _ 4 _ - _ 4 _= _ _ 8 = _ _ 1 1-9这几个数字在9*9的小格子里不能重复9 _ _ 7 _ _ _ _ __ _ 7 _ 2 _ 5 _ __ _ _ _ _ 3 _ _ 6_ 1 4 _ _ _ 9 _ __ 3 _ 9 _ 4 _ 7 __ _ 6 _ _ _ 8 2 _2 _ _ 1 _ _ _ _ _ _ _ 5 _ 4 _ 1 _ __ _ _ _ _ 8 _ _ 3把数字1-9填写到方格子里,使每 要求每横排,每竖排的数各不相同,3*3小方块里的数也不相同9 _ 5 _ _ _ _ _ 68 _ _ 4 _ _ 9 _ 7_ 7 _ _ _ _ 1 _ 3_ _ 1 _ 4 _ _ _ 55 6 4 _ 9 7 _ _ 2_ 9 _ 5 _ _ _ 8 __ _ 9 _ 3 8 _ _ 1_ _ 8 2 1 4 _ 6 9_ 2 _ _ _ _ _ _ _ ,在横线上填英文字母(1)f_ _ _ _(2)_o_ _ _ _(3)d_ _ _ _ _ _ _(4)_ _ _ _ _d_ _(5)_ _n_ _ _(6)_ _k_(7)_e_ _ _ _(8)_ _g_ _(9)_l_ _ _(10)_i_(11)_ _s_ _ _(12)_ _h_ _ _(13)_ _f_ _ _ _(14)_ _u_(15 填表,(1)猜想线段条数m与直线l上点数n有什么关系?(2)计算n=30时,m的值.直线l上点的个数 图形 线段总条数1 _______._______ 02 ____.______.___ 1A B3 ____.____.__.__ 3A B C4 ____.____._._.__ 6A B C D5 ____.____._._._._ 10A 用从1到9九个数字填空(不能重复):_ _ _ _ * _ = _ _ _ _结果不重要, 英语翻译1、an interesting place to go or thing to do_ _ _ _ _ _ _ i _ _2、talk with someone and ask him or her questions about something_ _ _ _ _ _ _ _ _3、under the surface of the ground_ _ _ e _ _ _ o _ n _4、something that gives people ple 根据中文提示,完成下列句子.每空限填一词I want to buy _ _ _ _ _ _ _ _ _ _ (空中填 1千克鱼和半千克猪肉)Please give him _ _ _ _ _ _ _ _ _(空中填 3箱苹果和一袋梨连词成句I,Bill,students,high,are,Sam,school,all,an 你有几种填法.1、4、9、_、_、_…… 英语翻译1、words that make something clear or say what something means _ _ _ _ _ _ _ _ _ _ _ 首字母是e 2、not working _ _ _ _ 尾字母是d 3、stretch out one 's body on the bed or ground _ _ _ 中间字母是i4、front area in a big offic 找规律,写单词.例:first second third fourth 1、fifth找规律,写单词.例:first second third fourth 1、fifth _ _ _ 2、ninth _ _ _ 3、thirteenth _ _ _ _ _ nineteenth