Question 1. [10] Let A be an additively written abelian group. Consider the endomorphism group of A End A := {a : A A la is an endomorphism}. Let us define + and on End A as follows : For a, B E End A, let a +B : A A be defined by (a + 3)(x) = a(x) + B(x) for a E A and a B = a : A A is the usual composition of maps. Show that (End A, +, ) is a ring.