Thread: Problem with proving

I need to show that A is a subset of B if and only if A union B is equal to B. Can somebody help me with this? Thanks

Originally Posted by Scorpy6

I need to show that A is a subset of B if and only if A union B is equal to B. Can somebody help me with this? Thanks

You need to show two things:

1. If then

2. If then

Now what have you tried and what problems are you having?

CB