1/(1×2)+1/(2×3)+1/(3×4)+……1/(49×50)=1/1-1/2+1/2-1/3+1/3-1/4+……+1/49-1/50=1-1/50=49/50中间抵消，求采纳
1/(1×2)+1/(2×3)+1/(3×4)+……1/(49×50)=1/1-1/2+1/2-1/3+1/3-1/4+……+1/49-1/50=1-1/50=49/50以上回答你满意么？
