Ask QS!!!Help me, please:)

shlingw

1.for a finite sequence of nonzero numbers, the number of  variations in sign is defined as the number of pairs
  of consecutive tetms of the sequence for  which the product of  the two consecutive terms  is negative. what is
  the number of variations in sign for the sequence 1,-3,2,5,-4,-6.
  answer : 3 or 5 ?

2.For all  positive integers m, (m) = 3m when m is odd and (m) =1/2m when m is even, which of the following is
   equivalent to (9)(6)?
   Answer: 81 or 27??

How to fix them, give me a hand ,please!

小姣龙

81

davidsfo

prep里面的答案是（27）啊

我是这样理解的

（9）x（6） = 81

但是注意题目选项是(81) 不是81

所以应该是（27） 因为（27）= 3x27 = 81

[此贴子已经被作者于2008-2-12 16:37:07编辑过]