1/x(x+3)+1/(x+3)(x+6)+---+1/(x+27)(x+30)
来源:学生作业帮助网 编辑:六六作业网 时间:2024/12/22 09:39:36
1/x(x+3)+1/(x+3)(x+6)+---+1/(x+27)(x+30)1/x(x+3)+1/(x+3)(x+6)+---+1/(x+27)(x+30)1/x(x+3)+1/(x+3)(x+6
1/x(x+3)+1/(x+3)(x+6)+---+1/(x+27)(x+30)
1/x(x+3)+1/(x+3)(x+6)+---+1/(x+27)(x+30)
1/x(x+3)+1/(x+3)(x+6)+---+1/(x+27)(x+30)
1/x(x+3)+1/(x+3)(x+6)+---+1/(x+27)(x+30)
=[1/x-1/(x+3)+1/(x+3)-1/(x+6)+---+1/(x+27)-1/(x+30)]/3
=[1/x-1/(x+30)]/3
=10/[x(x+30)]
这个数列的通项公式是 a=(1/3)(1/x -1/(x+3))
共 10相。所以 s=(1/3)(1/x -1/(x-30))
*-----------------------------------------------*| 6 4 X | 8 X X | X X 5 || X X X | X X X | X 7 8 || X X X | X X X | X X X ||---------------+---------------+--------------- || X X X | X X X | 5 1 X || X X X | X 6 X | X X X || 8 X X | 3 5 X | 2 X X ||
填九宫格帮帮忙.x x 6 x x 7 x x 98 x x x 3 x 1 x x 9 x x 6 x 5 x 3 x x x 3 x x x x 1 8x x x 9 x 1 x x x2 1 x x x x 6 x x x 6 x 7 x 3 x x 1 x x 9 x 2 x x x 47 x x 8 x x 5 x x
求一个数独答案X X X 9 X X X 8 2 X 6 3 X X 1 4 X 99 X 8 X X X X X XX X X 6 7 X 3 X XX 4 6 X 5 X 2 9 XX X 7 X 2 3 X X XX X X X X X 7 X 17 X 4 3 X X 6 2 X6 3 X X X 7 X X X
七年级下册政治复习提纲(山东人民出版社)第五单元是 青春的脚步 青春的气息别弄错了啊!格式:X X X X X X X X X 1、X X X X X X X X X X.2、X X X X X X X X X.3、X X X X X X X X X X X.
难倒爱因斯坦的九宫格X 7 X | X 8 1 | X X X |X X X | X 4 X | 7 5 9 |X X 5 | 7 X 9 | X 1 4 |5 X X | X X 8 | 3 9 X |3 9 6 | 4 X 7 | X X 2 |X 8 7 | 9 X X | X X X |4 X X | 6 X 5 | X X X | X X 4 | X X 1 |2 X X | X X X | X X X | X 3 X | X X X |X 6
如下9*9宫图如何填x x x 1 x x x 2 9x x 5 x x x x x 4x 6 8 x x x x x xx x x 7 x x 5 x xx 2 x x 6 x x 8 xx x 3 x x 9 x x xx x x x 5 x 1 6 x 4 x x x 3 x x x x 7 x x x x 2 x x x
解九宫格题目(X为未知数)9 X 2 X 7 X 8 X XX X 4 X X 9 X 6 X1 3 X 5 X X X X 24 X X 8 5 X X 1 XX 8 9 4 X 1 6 7 XX 1 X X 3 6 X X 88 X X X X 2 X 3 6X 5 X 6 X X 9 X XX X 7 X 4 X 2 X 1
计算:[(x^2 - 4)/(x^2 - x - 6) + (x+2)/(x-3)] / (x+1)/(x-3)
解方程x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6)
(x-1)/(x+3x+2)+6/(2+x-x)-(10-x)/(4-x)
x+2/x^2-x-6 + 2x/x^3-3x - x+1/x^2-6x+9
(x+2/x^2-x-6)-(2x/x^2-3x)-(x+1/x^2-6x+9)
已知3x*x-x=1,求6x*x*x+7x*x-5x+2000
x+2/x+1-x+4/x+3=x+6/x+5-x+8/x+7 x=?
(x+1-1/1-x)÷(x-x²/x-1) (x-4/x-x-6+ x+2/x-3)÷x+1/x-3
解决数独问题x 1 x 7 x x x 3 xx x x x 4 x 2 x x9 x 3 6 x 8 7 x 58 x x x x 9 x x xx x 2 x 5 x x x 4x 3 x x x x 6 x xx x x x x x x x 26 x x x x x x x 7x 5 4 1 7 x 9 8 x这道题我用了很多办法都没有头绪,请帮忙的朋友把解题的思
/X-3/-/X-1/
(3x/x-1)