Solution: Look at the first question from the elements of the set A: (Order? Z is 0, 1, 2, 3, ...)

x=2k+ 1？ K∈Z, which means that X takes odd numbers in all integers ...-9,-7,-5,-3,-1,1,3, 5, 7, 9, .....

x = 4k 1 = 2(2k 1)- 1？ K∈Z means that x takes some odd numbers in the integer? ....-9,-7,5,- 1, 1,5,7,9, .....

It's obvious? A=B？ Again, the second question? N is also a partial even number, and m is a full even number, so? MN。