请教一道小学奥数题题?

来源:百度知道 编辑:UC知道 时间:2024/06/10 18:35:25
1-1/(1+2)-1/(1+2+3)-1/(1+2+3+4)-…-1/(1+2+3+4+…+100)=?

要求:步骤详细,思路清晰,过程完整,易学会!

1/2*2-(1/2-1/3)*2-(1/3-1/4)*2-(1/4-1/5)*2- -(1/100-1/101)*2
=2(1/2-1/2+1/3-1/3+1/4-1/4+1/5- -1/100+1/101)
=2*1/101=2/101

幽幽文竹 很好很强大……

1-1/(1+2)-1/(1+2+3)-1/(1+2+3+4)-......-1/(1+2+3+4+...+100)
=1-1/3-1/6-1/10-...-1/5050
=2/2-2/(6*2)-2/(10*2)-...-2/(5050*2)
=2*(1/2-1/2+1/3-1/3+1/4-1/4+1/5-...-1/100+1/101)
=2*(1/101)
=2/101