采纳一下谢谢
1/1×2×3+1/2×3×4+1/3×4×5+1/4×5×6+1/5×6×7+1/6×7×8=（1/1×2-1/2×3+1/2×3-1/3×4+1/3×4-1/4×5+1/4×5-1/5×6+1/5×6-1/6×7+1/6×7-1/7×8）÷2=（1/1×2-1/7×8）÷2=（1/2-1/56）÷2=27/56÷2=27/112
