as always, to show that one set is a subset of another, you must show that every element in the first set is found in the other as well. thus, you must show,

try that and see where you get.

as for showing that equality need not hold, just come up with an example where you have the described subset relationship without equality. having trouble coming up with such an example, consider drawing Venn diagrams to come up with an idea. you will see what you need to do