Question

If set M consists of all integer numbers x such that 3<x<7, and set N consists of all integer numbers x such that 6≤x≤9, list:
M=...
N=...
M∪N=...
M∩N=...
M∖N=...
N∖M=...

Answer 1

I would start by listing the sets:
M = {4, 5, 6}
N = {6, 7, 8, 9}

Now do what it asks for in each part.
I assume you know what your notations mean and do.

Actually I have never see M∖N

Answer 2

Listing M would be the set of all the elements in M, which would be 4,5,6. Listing N would be the same idea, the answer being 6,7,8,9. The third one is the union of the two sets, so you list out all the elements of M and N, but because the number 6 is listed twice, you only write it once. The answer is 4,5,6,7,8,9. The fourth one is the intersection of the two sets, or what they have I common. The only number that is in both sets in 6, so that's the answer. In the fifth and sixth ones, the diagonal line is not a division sign, but a subtraction sign, as we are dealing with sets. Since the fifth one is M/N, we are subtracting the numbers in set N from the numbers in set M. As, once again, 6 is the only common number, subtracting that from set M would leave you with only two numbers, those being 4 and 5. The sixth one is just like the fifth, except it is N/M, so you would subtract the intersection, or I this case, the number six, from the numbers in set N, which would leave you with only three numbers, those being 7,8, and 9. Hope this helped. :)