1-1/2+1/3-1/4+1/5-1/6…+1/99-1/100）/（1/51+1/52+1/53+…+1/99+1/

(1-1/2+1/3-1/4..-1/100) =(1+1/2+1/3+1/4..+1/100)-2*(1/2+1/4+1/6+..1/100) =(1+1/2+1/3+1/4...+1/100)-(1+1/2+1/3+1/4+..1/50) =1/51+1/52+1/53..+1/100 所以你的答案是1,懂了吗?