1/(1*3) + 1/(3*6) + 1/(6*9) + 1/(9*12) + …+1/(96*99)
=1/3 + 1/3*(1/3-1/6+1/6-1/9 + .-1/96+1/96-1/99 )
=1/3 + 1/3*(1/3-1/99)
=1/3*(1+1/3-1/99)
=395/27你确定这是正确答案？我觉得没错的说~答案怎么可能是27分之395呢？还有第四行中的那个1是怎么来的=【1/3】*1+【1/3】*(1/3-1/99)=【1/3】*(1+1/3-1/99)提取公因式