100-1又1/2-2又5/6-3又1/12-4又9/20-5又29/30
=100-(1+1/2)-(3-1/6)-(4+9/20)-(6-1/30)
=100-(1+3+4+6)-(1/2-1/6+9/20-1/30)
=100-14-(1/2-1/6+9/20-1/30)
=86-(1/2-1/6+9/20-1/30)
裂项:
原式=86-3/4=85又1/4
1\/2加5\/6加11\/12加19\/20加29\/30
回答:约等于5.666667
1\/2+5\/6+11\/12+19\/20+29\/30=
原式=1-1\/2+1-1\/6+1-1\/12...+1-1\/90 =1*9-(1\/2+1\/6+1\/121\/20+1\/30+1\/42+1\/56+1\/72+1\/90)=9-(1-1\/2+1\/2-1\/3+1\/3-1\/4+1\/4...+1\/8-1\/8+1\/9-1\/9+1\/10-1\/10)=9-(1-1\/10)=9-9\/10=8又1\/10 注:1\/6=1\/2*1\/3 1\/12=1\/3*1\/4...
1\/2,-5\/6,11\/12,-19\/20,29\/30,-41\/42,___,___…
所以接下来两项是55\/56,-71\/72
1\/2+5\/6+11\/12+19\/20+29\/30=
=1-1+1\/2+1-1\/2+1\/3+1-1\/3+1\/4+1-1\/4+1\/5+1-1\/5+1\/6 =4+1\/6 =4又1\/6
1\/2+5\/6+11\/12+19\/20+29\/30+…+379\/380简便方法怎么算?
2=1*2,6=2*3,12=3*4,20=4*5……每一项写成 (n*(n+1)-1)\/(n*(n+1)),这个是可以拆的,可能需要一点经验:=1-1\/(n*(n+1))=1-(1\/n-1\/(n+1))=1-1\/n+1\/(n+1)把整个数列重新写一下就变成了:(1-1\/1+1\/2)+(1-1\/2+1\/3)+(1-1\/3+1\/4...
1\/2+5\/6+11\/12+19\/20+29\/30要简便运算,还要过程,回答正确提分
原式=1﹣1/2+﹙1﹣1/6﹚+﹙1﹣1/12﹚+﹙1﹣1/20﹚+﹙1﹣1/30﹚=5-﹙1/2 +1/6+1/12+1/20+1/30﹚=5-﹙1/2+1/2-1/3+1/3-1/4+1/4-1/5﹢ 1/5-1/6﹚=4+1/6=25/6
(-9又1\/3)-|-4又5\/6|+|0-5又1\/6|-2\/3的计算过程
(-9又1\/3)-|-4又5\/6|+|0-5又1\/6|-2\/3 =(-28\/3)-29\/6+31\/6-2\/3 =-30\/3+2\/6 =-30\/3+1\/3 =-29\/3 如果不懂,请追问,祝学习愉快!
计算题1\/2+5\/6+11\/12+19\/20+29\/30+...9701\/9702+9899\/9900=
有这样的思路,接下来这样写(1-1\/2+1-1\/6+1-1\/12+1-1\/20+1\/30...+1-1\/9900)算下里面有多少个1,然后1\/6,1\/12,1\/20等等都可以拆开1\/2-1\/3+1\/3-1\/4~~~都可以消掉,最后的结果还是你自己算把,不能把答案全部写出来,那样一点意义都没有了 ...
1\/2+5\/6+11\/12+19\/20+29\/30
1\/2+5\/6+11\/12+19\/20+29\/30 =1\/2+1-(1\/2-1\/3)+1-(1\/3-1\/4)+1-(1\/4-1\/5)+1-(1\/5-1\/6)=4+(1\/2-1\/2+1\/3-1\/3+1\/4-1\/4+1\/5-1\/5+1\/6)=4+1\/6=25\/6
数字推理题不会啊,怎么推理啊 脑子都大了。
5,3,2,1,1,() A-3 B-2 C 0 D2 选C. 2.乘除关系。又分为等比、移动求积或商两种 (1)等比。从第二项起,每一项与它前一项的比等于一个常数或一个等差数列。 8,12,18,27,(40.5)后项与前项之比为1.5. 6,6,9,18,45,(135)后项与前项之比为等差数列,分别为1,1.5,2,2.5,3 (2)移动求积...