[求助]GWD Math problems

jtcjxk

1.What is the value of (x-y)4?

(1) The product of x and y is 7

(2) x and y are integers.

Answer is together are not sufficient. But I think both together are sufficient, because x and y can be either 1,7 or -1, -7.  (1-7)4=(-6)4=(-1+7)4  Am I right or not?

2. If y is the smallest positive integer such that 3, 150 mutiplied by y is the square of an integer, then y must be

Answer is 14. I have no idea how to get it.

Thans a lot!!! 

jesuischong

1，如果是4次方，我认为你的答案是对的

2，我觉得答案应该是2，因为，3*150=3*3*5*5*2,所以只要一个2就可以满足条件了

fennyhx

3,150=5*5*9*2*7所以就差了2*7=14这样条件就满足了，答案没错。