(2a-b-c)/[(a-b)(a-c)] + (2b-a-c)/[(b-c)(b-a)] + (2c-a-b)/[(c-b)(c-a)]=[(a-b)+(a-c)]/[(a-b)(a-c)] +[(b-a)+(b-c)]/[(b-c)(b-a)] +[(c-a)+(c-b)]/[(c-b)(c-a)]=[(1/(a-b))+(1/(a-c))]+[(1/(b-c))+(1/(b-a))]+[(1...