Question 1: let G= a,+a,X+a,X* |aota, + az=0} Prove that G is a group undet addition? Question 3: Let G be a group with exactly 4 elements Prove that Gis abelian? IPleas ineed to answet all questions] Question: let a and b be elements in a finite group G Prove that the ardek (ab) is equal to the ordet of (ba)?