I have no freaking Idea on how to do this
4) R {1,2,3,4,7} T{3,5,6,7} What is the intersection of R & T?
5) What are the subsets of {-2,-1}?
The intersection is the set of elements common to both sets. In this case,
R∩T = {3,7}
The subsets of {-2,1} are
Ø, {-2}, {1}, {-2,1}
There are 2n subsets of a n-element set.
If you really have no freaking idea on this, I suggest you read your text and talk to your teacher. Really.