(a＋b＋c)(1/a＋1/b＋1/c)−３
=(a+b+c)*(1/a) + (a+b+c)*(1/b) + (a+b+c)*(1/c) - 3
={1 + (b+c)/a} + {1 + (c+a)/b} + {1 + (a+b)/c} - 3


=((b＋ｃ))/a＋((c＋a))/ｂ＋((a＋b))/ｃ