1\/1X2+1\/2X3+1\/3X4...1\/99X100
1\/1X2+1\/2X3+1\/3X4+...+1\/99X100 = 1\/1-1\/2+1\/2-1\/3+1\/3-...+1\/99-1\/00 = 1-1\/100 = 99\/100
1\/1X2+1\/2X3+1\/3X4+...+1\/99X100 怎么简便计算。。过程..
1\/1X2+1\/2X3+1\/3X4+...+1\/99X100 =(1-1\/2)+(1\/2-1\/3)+(1\/3-1\/4)+...+(1\/99-1\/100)=1-1\/100 =99\/100 乘法分配律 简便计算中最常用的方法是乘法分配律。乘法分配律指的是ax(b+c)=axb+axc其中a,b,c是任意实数。相反的,axb+axc=ax(b+c)叫做乘法分配律的逆运用...
1\/1X2+1\/2X3+1\/3X4+...+1\/99+100=
1\/1X2+1\/2X3+1\/3X4+...+1\/99X100 =(1-1\/2)+(1\/2-1\/3)+(1\/3-1\/4)+...+(1\/99-1\/100)=1-1\/100 =99\/100
1\/1x2+1\/2x3+1\/3x4+...+1\/99x100学等差数列求和公式
=(1+2+3+...+99+100)*(1+1.2)=(1+2+3+...+99+100)*2.2 =[(1+100)*100\/2]*2.2 =5050*2.2 =11110 中间用的是等差数列求和公式
1\/1x2+1\/2x3+1\/3x4+...1\/99x100
解:1\/1X2+1\/2X3+1\/3X4+...+1\/99X100 =(1-1\/2)+(1\/2-1\/3)+(1\/3-1\/4)+...+(1\/99-1\/100)=1-1\/2+1\/2-1\/3+1\/3-1\/4+...+1\/99-1\/100 (中间两项两项正负抵消)=1-1\/100 =99\/100
1\/1X2+1\/2x3+1\/3x4+1\/4x5+...+1\/98x99+1\/99x100求结果!!!
1\/1乘2等于1\/1减1\/2 同理2乘3分之一等于2分之一减去3分之一 上式等于1\/1-1\/2+1\/2--1\/3+1\/3...-1\/99+1\/99-1\/100等于99\/100
求解答:1\/1x2+1\/2x3+1\/3x4...1\/99x100. 奥数不会
这个是有裂项公式的,1\/n(n+1)=1\/n-1\/(n+1)根据公式,原式=1-1\/2+1\/2-1\/3+……-1\/99+1\/99-1\/100 中间的式子都可以抵消,则得到原式=1-1\/100=99\/100
一道数学题急 1\/1x2+1\/2x3+1\/3x4+...+1\/99x100=?
1\/1x2+1\/2x3+1\/3x4+...+1\/99x100 =1-1\/2+1\/2-1\/3+.+1\/98-1\/99+1\/99-1\/100 =1-1\/100 =99\/100
1\/1*2+1\/2*3+1\/3*4+.+1\/99*100怎样简便运算
解:1\/1x2=1-1\/2(1)1\/2x3=1\/2-1\/3(2)1\/3x4=1\/3-1\/4(3)...1\/98x1\/99=1\/98-1\/99(98)1\/99x100=1\/99-1\/100(99)除了(1)和(2)之外,其中任意一项的前项和前一项的后项能够互相抵消,后项能和后面一项的前项相互抵消,即第(3)到第(98)项,然后第一项的后项...
数学计算题:1\/1X2+1\/2X3+1\/3X4+...+1\/99x100=? 请写出计算过程~_百度...
1\/1*2=1\/1-1\/2 1\/2*3=1\/2-1\/3……所以原式=1-1\/2+1\/2-1\/3+1\/3-1\/4+……-1\/99+1\/99-1\/100=99\/100