如题所述
第1个回答 2017-02-17
1/(2×3×4)+1/(3×4×5)+……+1/(10×11×12)
=1/2×【1/(2×3)-1/(3×4)+1/(3×4)-1/(4×5)+……+1/(10×11)-1/(11×12)】
=1/2×【1/(2×3)-1/(11×12)】
=1/2×【1/6-1/132】
=1/2×7/44
=7/88本回答被网友采纳
=1/2×【1/(2×3)-1/(3×4)+1/(3×4)-1/(4×5)+……+1/(10×11)-1/(11×12)】
=1/2×【1/(2×3)-1/(11×12)】
=1/2×【1/6-1/132】
=1/2×7/44
=7/88本回答被网友采纳