数学计算题:1\/1X2+1\/2X3+1\/3X4+...+1\/99x100=? 请写出计算过程~
所以原式=1-1\/2+1\/2-1\/3+1\/3-1\/4+……-1\/99+1\/99-1\/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\/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\/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\/1×2 +1\/2×3 +1\/3×4 +…1\/99×100 =? 过程。。。
1\/1x2=1-1\/2然后1\/2x3=1\/2-1\/3依次类推1\/99x100=1\/99-1\/100消去中间项余1-1\/100=99\/10O
乘法的分配律怎么算?
乘法分配律指的是两个数的和与一个数相乘的积,可以先把它们分别与这个数相乘再相加,结果不变乘法分配律是简便计算中最常用的方法。举例
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...
1\/1乘2乘3+1\/2乘3乘4+...+1\/98乘99乘100=
1\/(n-1)n-1\/n(n+1)=(n+1-n+1)\/(n-1)n(n+1)=2\/(n-1)n(n+1),于是1\/(n-1)n(n+1)=(1\/2)[1\/(n-1)n-1\/n(n+1)]所以原式=(1\/2)[(1\/1x2-1\/2x3)+(1\/2x3-1\/3x4)+++++(1\/97x98-1\/98x99)+(1\/98x99-1\/99x100)]=(1\/2)(1\/2-1\/9900)...
1\/1×2十1\/2x3十1\/3×4十……十1\/99x100=?怎样做
1\/1×2十1\/2x3十1\/3×4十……十1\/99x100 =1-1\/2+1\/2-1\/3+1\/3-1\/4+…+1\/99-1\/100 =1-1\/100 =99\/10 利用裂项求和法 1\/(1x2)=1-1\/2
一定要帮我啊!(1\/1x2)+(1\/2x3)+(1\/3x4)+(1\/4x5)+.+(1\/99x100)=?
因为 1\/1×2 = 1 - 1\/2 1\/2×3 = 1\/2 - 1\/3 依此类推 1\/99×100 = 1\/99 - 1\/100 所以 原式 = 1 - 1\/2 + 1\/2 - 1\/3 + 1\/3 - 1\/4 + ...+ 1\/99 - 1\/00 = 1 - 1\/100 = 99\/100