3 / 4, 1 / 2, 1 / 3, (), 4 / 27, () 3/4、1/2、1/3、（）、4/27（）. Write why!

3 / 4, 1 / 2, 1 / 3, (), 4 / 27, () 3/4、1/2、1/3、（）、4/27（）. Write why!

3 / 4, 1 / 2, 1 / 3, (2 / 9), 4 / 27, (8 / 81)
Rule: multiply the former number by 2 / 3 to get the latter number; in other words, the latter number is 2 / 3 of the former number
Because: (1 / 2) / (3 / 4) = 1 / 2 * 4 / 3 = 2 / 3
(1/3)÷(1/2)=1/3*2=2/3
So, 2 / 3 * 1 / 3 = 2 / 9
2/3*4/27=8/81

Find the rule: half, three and half, seven, ten, twenty, [], []

1/2 ,7/2 ,7 ,10 ,20 (23) (46)
+3 * 2 alternate

What's the rule of negative half, 1, - 2,4, - 8,16? (expressed in n) hurry!
Denoted by n (n is a positive integer)

(n + 1) power of (- 1) multiplied by (n-1) power of 2

Find the law: 1 / 2, 1 / 3, 2 / 3, 1 / 3, 1 / 4, 1 / 2, 3 / 4, 1 / 2, 1 / 4. What are the 20 numbers of the earth?
OK, 100 more

1/2
-1/3,2/3,-1/3
1/4,-2/4,3/4,-2/4,1/4
-1/5.2/5,-3/5,4/5,-3/5,2/5,-1/5
1/6,-2/6,3/6,-4/6,5/6,-4/6,3/6,-2/6,1/6
Count, the 20th number is - 4 / 6 = - 2 / 3