Dokažite identitet a1a2(a1+a2)+a2a3(a2+a3)+…+ana1(an+a1)=a2a1(a1+a2)+a3a2(a2+a3)+…+a1an(an+a1).\frac{a_1}{a_2(a_1 + a_2)} + \frac{a_2}{a_3(a_2 + a_3)} + \ldots + \frac{a_n}{a_1(a_n + a_1)} = \frac{a_2}{a_1(a_1 + a_2)} + \frac{a_3}{a_2(a_2 + a_3)} + \ldots + \frac{a_1}{a_n(a_n + a_1)}.a2(a1+a2)a1+a3(a2+a3)a2+…+a1(an+a1)an=a1(a1+a2)a2+a2(a2+a3)a3+…+an(an+a1)a1.