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> Let $(G, ∗)$ be a finite abelian group and $G = \{a\_1, a\_2, . . . , a\_n\}$. Let $a\_1 ∗a\_2 ∗· · · ∗a\_n = x$. Show that $x ∗ x = e$, where $e$ is the identity of $(G, ∗)$.
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Please give me head start on how to proceed. I am completely blank.