3又(1/3) +5又(2/4) +7又(3/5) +9又(4/6)=10/3+22/4+38/5+58/6 =20/6+58/6+110/20+152/20=78/6+262/20=13+13.1=26.1 1又(2/3)+ 2又(3/4)+ 3又(4/5) +4又(5/6)=5/3+11/4+19/5+29/6 =10/6+29/6+55/20+76/20=39/6+131/20=6.5+6.55=13.05 親,您的采納是我的動力,