六年级数学题/(1*2)+1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+.+1/(99*100)=?1/(1*2)+1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+......+1/(99*100)=?
来源:学生作业帮助网 编辑:作业帮 时间:2024/11/27 21:34:45
六年级数学题/(1*2)+1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+.+1/(99*100)=?1/(1*2)+1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+......+1/(99*100)=?
六年级数学题/(1*2)+1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+.+1/(99*100)=?
1/(1*2)+1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+......+1/(99*100)=?
六年级数学题/(1*2)+1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+.+1/(99*100)=?1/(1*2)+1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+......+1/(99*100)=?
原式=1-1/2+1/2-1/3+1/3-1/4.+1/99-1/100=1-1/100=99/100
因为1/(1*2)=1-1/2;1/(2*3)=1/2-1/3;1/(3*4)=1/3-1/4......以此类推
所以,原式=(1-1/2)+(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)......+(1/99-1/100)=1-1/100=99/100
从这道题中,你会发现一个规律,那就是:1/(a*(a+1))=1/a-1/(a+1)(其中,a>0)
=1-1/2+1/2-1/3+1/3-1/4。。。。。。。。1/98-1/99+1/99-1/100=99/100
答案:99/100
解题方法:=(1/1-1/2)+(1/2-1/3)+(1/3-1/4)+......+(1/99-1/100)
=1-1/100
=99/100