Question 27102
Hi,

To show it's a group you must show four things.

1) Closure
2) Associativity
3) Existence of identity
4) Existence of inverses

None of these are particularly difficult, which one are you having trouble with? It doesn't look immediatly associtive, but if you work through it, you will see it is.

To see if the group is abelian you must check if *[tex ab=ba\,\forall a,b\in G] Do the multiplication of two general elements both ways, and see if you get the same thing - you shouldn't.

Write back with the part you are stuck on and I'll see if I can help with that bit specifically.

Hope that helps,

Kev.