2 又1/2×5+4又1/5×8+……+100又1/149×152+102又1/152×155 一定要简算的!

问题描述:

2 又1/2×5+4又1/5×8+……+100又1/149×152+102又1/152×155 一定要简算的!

2又1/2x5+4 又1/5x8+6又 1/8x11+...+100又 1/149x152+102又 1/152x155=(2+4+6+……+100+102)+(1/2-1/5+1/5-1/8+1/8-1/11+……+1/149-1/152+1/152-1/155)÷3=(2+102)×51÷2+(1/2-1/155)÷3=2652+51/310=2652...