TT gwd-5- 5/7/8

5-5: The infinite sequence a₁,a₂,,,,,a_n,,,is such that a₁=2, a₂=-3, a₃=5, a₄=-1, and a_n=a_n-4 for n>4. what is the sum of the first 97 terms of the sequence?

- for there is obviously some direct relationship,but unfortunately i could not see....

5-7: what is the value of |x+7|?

1) |x+3|=14

2) (x+2)²=169

- From any of the above equation we could get the value of x, therefore i choose D, but C in answer sheet. why?

5-8:

                                          3

                                          3

                                          3

    x                            3

            Note:  Figure not drawn to scale.

The figure above represents a square garden that is divided into 9 rectangular regions with indicated dimensions in meters.  The shaded regions are planted with peas, and the unshaded regions are planted with tomatoes.  If the sum of the areas of the regions planted with peas is equal to the sum of the areas of the regions planted with tomatoes, what is the value of x?

A.     0.5

B.     1

C.     1.5

D.     2

E.      2.5

unfortunately i didnot get any clue of solving this question, anybody can help with the above 3 questions?

把规律找到
这个排列四个数一组循环
2，-3，5， -1，2，-3，5， -1，2，-3，5， -1。。。。。
这四个数的和是3， 一共有[97/4]=24个(中括号代表取整数), 最后还剩一个数就是2
所以和为3*24+2

每个式子得出答案都是两个,只有两式联立才是唯一答案

第三个题请把图贴出来

我觉得第三题不难,就是算起来麻烦一点,请注意那个大框是一个square,而里面的9个格子都是矩形,你已经知道了正方形的边长是9了,然后又告诉你那三段都是3,你把不知道的边用x表示出来,然后把9个格子的面积加起来等于81,即正方形的面积,然后就可以算出x了

认真算算,没问题的