prep几道数学求助..

临莅

昨天半夜模考。。数学狂错12道。。不过居然有49。。大概错的没被抽到吧。。

For every positive even integer n,the function h(n) is defined to be the product of all the even integers from 2 to n,inclusive.If p is the smallest prime factor of h(100)+1,the P is:

A,2~10  b. 10~20 c. 20~30 d.30~40 e.greater than 40

If n and y are positive integers and 450y=n^3 which of the following must be an integer?

1,y/(3*2^2*5)

2,y/(3^2*2*5)

3,y/(3*2*5^2)




On the number line,the distance between x and y is greater than the distance between x and z.

Does z lie between x and y?、
（1）xyz<0
(2) xy<0

快乐小龙

第二题，将450分解，2*5*5*3*3
因为N^3=Y450, 那么可以推出=2*2*5*3
然后你去对对照选项，A正确

第三题：应该选择E把
X-Y>X-Z, X-z=z-y?
条件1：只能推出其中三个中一个小于0，不充分
条件2：x, y一个大于0一个小于0，不知道Z的方向，不充分
结合条件也推不出