1/6+1/12+1/20+30/1+40/1的简便算法
来源:百度知道 编辑:UC知道 时间:2024/05/06 04:19:02
我觉得你的题目打错了
题目可能是
1/6+1/12+1/20+1/30+1/42
但都是用裂项法...
1)(没打错)
原式=1/6+1/12+1/20+1/30+1/40
=1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+1/40
=1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/40
中间很多项都抵消
So 原式=1/2-1/6+1/40=43/120
2)打错了
原式=1/6+1/12+1/20+1/30+1/42
=1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+1/(6*7)
=1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7
中间很多项都抵消
So 原式=1/2-1/7=5/14
希望你满意我的答复...谢谢...
1/6+1/12+1/20+1/30+1/40
=(1/2-1/3)+(1/3-1/4)+)+(1/4-/5)+(1/5-1/6)+1/40
=1/2-1/6+1/40=1/3+1/40=43/120
你题目是不是搞错了?
1/6+1/12+1/20+1/30+1/40
=(1/6+1/12)+(1/20+1/40)+1/30
=1/4+3/40+1/30
=13/40+1/30
=43/120
应该这样吧
在等等高手也成
1+1/3+1/6+........+1/55
5/6=1/?+1/?+1/?
1/2+1/6+1/12+1/20+1/30
1/6+1/8+1/10+1/12+..........+1/202=?
1/2+1/4+1/6+1/8+.......+1/n=?
-1/2-1/6-1/12-1/20-``````````````-1/4026042
1/2+1/6+1/12+......+1/1980+1/2070=?
(1/2) (1/4+1/6)=
(1/2-1)*(1/3-1)*(1/4-1)*(1/5-1)*(1/6-1)*(1/7-1)*(1/8-1)*(1/9-1)*(1/10-1)
1/2 ,1/3 ,1/6 /1/6 ,()