0,1,3,8,21, () fill in the numbers according to the rules

0,1,3,8,21, () fill in the numbers according to the rules

The rules of 0, 1, 3, 8, 21, (55), 144 are as follows: 0 --- 1 --- 3 --- 8 --- 21 --- 55 --- 1441 --- 2 --- 5 --- 13 -- (34) --- 891 --- 3 --- 8 -- (21) --- 55 --- 144, first calculate the difference between the two numbers (see the second line) and then calculate the difference between the two numbers (see the third line)

Mathematical problems about positive and negative proportion
M and N are two related quantities, and a and B, C and D (both not zero) are the corresponding values of the two groups, as shown in the following table:
┏━┯━┯━┓
┃M │a │b ┃
┠—┼—┼—┨
┃N │c │d ┃
┗━┷━┷━┛
(1) If a: C = B: D, then M is proportional to n
(2) If a × C = B × D, then M is proportional to n
(3) If a + C = B + D, then M is proportional to n
Fill in the brackets with "positive" or "negative"

Zheng
back
back

What are the categories of natural numbers?

① According to parity, it can be divided into odd number and even number
② According to the number of factors, it can be divided into prime number, composite number and 1 (neither prime nor composite number)

Divide the nine numbers 39, 45, 49, 56, 60, 70, 78, 84 and 91 into three groups to make the product of each group equal
Explain the equation of uncertainty in detail

Solution 39 = 3 × 13
45=3²×5
49=7²
56=2³×7
60=2²×3×5
70=2×5×7
78=2×3×13
84=2²×3×7
91=7×13
∴39×70×84=78×49×60=45×56×91
The numbers of the three groups are 39,70,84 respectively,
49、60、78,
45、56、91.

How many meters is 1000 square meters
How to convert meters into square meters

20m x 50m

Translation of 3A on page 64

David Smith in North London has a big bellied pig named Connie. "Big bellied pig is the best pet," David said. "She watches TV with me every night on the sofa. She is my best friend." anyway, life with pigs is not always perfect. "When I first brought her back, she was very young, ”David said, "but she eats a lot. Now she is too old to sleep in the house, so I made a special house for her. Pigs need a lot of care. Sometimes I don't have enough time to accompany her."

The greatest common factor of 14 and 42 is (?) The least common multiple is ．

Because 14 and 42 are multiples, the greatest common factor of 14 and 42 is 14, and the least common multiple is 42

How to solve the problem that the ratio of X to 1 / 2 is equal to 1 / 5 to 1 / 4?

X = 1 / 20

It is known that rational numbers a and B satisfy a > b, which is the size of / A / and / B /
This is a question of grade one,

1.a=2,b=1
|a|=2,|b|=1
|a|>|b|
2.a=1,b=-1
|a|=1,|b|=1
|a|=|b|
3.a=1,b=-2
|a|=1,|b|=2
|a|

Uncle Li has 45 chickens and ducks in his family, which is four times as many as ducks. How many chickens and ducks does Uncle Li have?
How did you figure it out,

Let x ducks, 4x chickens, x + 4x = 45, x = 9, so 9 ducks, 36 chickens!