1/1*2*3+1/2*3*4+……+1/48*49*50的计算方法?

如题所述

提示:根据分数裂项公式计算。

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第1个回答  2020-08-20
可以用partial fraction化简成两个telescopic series做:
1/[n(n+1)(n+2)] = (-1/2)[1/(n+1) - 1/n] + (1/2)[1/(n+2) - 1/(n+1)]
1/1*2*3+1/2*3*4+……+1/48*49*50
= (-1/2)[1/2-1 + 1/3 - 1/2 + ... + 1/49 - 1/48] + (1/2)[1/3 - 1/2 + 1/4 - 1/3 + ... + 1/50 - 1/49]
= (-1/2)[-1+1/49] + (1/2)[-1/2+1/50]
= 306/1225

1\/1*2*3+1\/2*3*4+……+1\/48*49*50的计算方法?
提示:根据分数裂项公式计算。

1\/1*2*3+1\/2*3*4+```+1\/48*49*50=?
=(1\/1*2-1\/2*3+1\/2*3-1\/3*4+...+1\/48*49-1\/49*50)÷2 =(1\/1*2-1\/49*50)÷2 =(1\/2-1\/2450)÷2 =612\/1225÷2 =306\/1225

1\/1x2x3+1\/2x3x4+···+1\/48x48x50=用简便算法怎么算
1\/1x2x3 、1\/2x3x4 可以写成:1\/n x(n + 1)x (n + 2) 或者 1\/(n - 1)x n x (n + 1)1\/48x48x50 则写成:1\/n x n x (n + 2)所以未知解

1\/1×2×3+1\/2×3×4+1\/3×4×5+1\/4×5×6+...+1\/48×49×50的计算过 ...
=(1\/2)*(1\/1×2-1\/49×50)=(1\/2)*(1224\/2450)=612\/2450 =306\/1225

计算1\/1*2*3+1\/2*3*4+1\/3*4*5+.+1\/48*49*50
计算1\/1*2*3+1\/2*3*4+1\/3*4*5+.+1\/48*49*50 1\/1*2*3+1\/2*3*4+1\/3*4*5+...+1\/48*49*50 =(1\/1*2-1\/2*3+1\/2*3-1\/3*4+1\/3*4-1\/4*5+……+1\/48*19-1\/49*50)÷2 =(1\/1*2-1\/49*50)÷2 =(1\/2-1\/2450)÷2 =1\/4-1\/4900 =12...

1\/1X2X3+1\/2X3x4+…+1\/48X49X50
1\/1X2X3+1\/2X3x4+…+1\/48X49X50 =(1\/1X2-1\/2X3+1\/2X3-1\/3x4+…+1\/48X49-1\/49X50)÷2 = (1\/1X2-1\/49X50)÷2 =(1\/2-1\/2450)÷2 =1224\/2450÷2 =306\/1225

1\/(1*2*3)+1\/(2*3*4)+...+1\/(48_49_50)
1\/1×2×3=1\/2(1\/1×2-1\/2×3)1\/2×3×4=1\/2(1\/2×3-1\/3×4)1\/3×4×5=1\/2(1\/3×4-1\/4×5)……1\/48×49×50=1\/2(1\/48×49-1\/49×50)∴原式=1\/2【1\/1×2-1\/2×3+1\/2×3-1\/3×4+……+1\/48×49-1\/49×50】=1\/2【1\/2-1\/49×50】= ...

1\/1*2+1\/2*3+1\/3*4+……+1\/48*49+1\/49*50=?
1\/(1*2)+1\/(2*3)+1\/(3*4)+……+1\/(48*49)+1\/(49*50)=(1-1\/2)+(1\/2-1\/3)+(1\/3-1\/4)+...+(1\/48-1\/49)+(1\/49-1\/50)=1-1\/2+1\/2-1\/3+1\/3-1\/4+...+1\/48-1\/49+1\/49-1\/50 =1-1\/50 =49\/50 同学,提醒一下,在获得答案后,别忘了及时采纳哦,...

数学问题:1\/1X2 +1\/2x3+1\/3x4+...1\/48x49+1\/49x50的规律、过程、得数...
有一个式子:1\/a(a+1)=1\/a-1\/a+1 应用到这里 1\/1X2 +1\/2x3+1\/3x4+...1\/48x49+1\/49x50 =(1-1\/2)+(1\/2-1\/3)+(1\/3-1\/4)+...+(1\/49-1\/50)=1-1\/2+1\/2-1\/3+1\/3-1\/4+...1\/49-1\/50 (中间的都可以约)=1-1\/50 =49\/50 希望帮助到你,望采纳,...

1\/(1×2)+1\/(2×3)+1\/(3×4)...+1\/(48×49)+1\/(49×50)等于多少?
可以如下分析思考:1\/(1×2)+1\/(2×3)+1\/(3×4)...+1\/(48×49)+1\/(49×50)= (1 -1\/2) + (1\/2 - 1\/3) + (1\/3 - 1\/4) + ... + (1\/48 - 1\/49 + (1\/49 - 1\/50)= 1 - 1\/50 = 49\/50

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