.hey guys having problems with this question.

List the elements in the following sets:

1.

My Answer:

Elements x = 1,2,3,4 what about 0 ?

2.

My Answer:

Elements x = -4,-3,-2,0,1,2,3,4

3.

My Answer:

is not real, x=0 is the only solution

so I know , but dont know how to find from

4.

My Answer:

I know Q is rational numbers but dont know how to find this one.

5.

My Answer:no elements

This is just an empty set so would it be elements: ?

Any help with these 5 questions would be much appreciated.