你好：（1+1/2)*(1+1/4)*.*(1+1/10)*(1-1/3)*(1-1/5)*.(1-1/9)=(1+1/2)*(1+1/4)*(1+1/6)*(1+1/8)*(1+10/1)*(1-1/3*.*(1-1/9)=3/2*5/4*7/6*9/8*11/10*2/3*4/5*6/7*7/8*8/9=(3/2*2/3)(5/4...