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Why are prime numbers and composite numbers
There is no difference between prime number and composite number in nature, which is separated for the convenience of research
In mathematics, prime numbers are defined as natural numbers that can be divided by themselves and 1 (I think it's a bit nonsense to be divided by 1, but that's what the mathematical definition says), that is, except 1 and itself, all other numbers have remainder, such as 2, 3, 5, 7, 11 and so on
Of course, if you calculate carefully, 0 meets this condition (including 1). Unfortunately, in the study of number theory, natural numbers start from 1 and do not include 0 and negative numbers. Therefore, 0 is not a prime number. At the same time, negative numbers are not divided into prime numbers and composite numbers. Therefore, although - 5 and - 6 are integers, they cannot be divided into prime numbers and composite numbers, That is: integers, composite numbers and prime numbers are not the same concept. Not all integers can be divided into composite numbers of prime numbers
All natural numbers except prime numbers are composite numbers
In addition, 1 is a special number, which also conforms to the original definition of prime number. However, it is stipulated that 1 is not a prime number, nor a composite number. This is also stipulated for the purpose of studying problems
Therefore, the definition of prime number is: except 1, the number that can only be divided by 1 and itself is prime number
I wonder if you understand
Is 2 prime or composite
Prime number
Two is prime or composite
Prime number
If a is prime and B is composite, then ()
A. a+（b+2）B. （a+2）×bC. （a+2）÷bD. （a-2）÷b
According to the meaning of composite number, in the four formulas of a + (B + 2), (a + 2) × B, (a + 2) △ B, (A-2) △ B, because B is a composite number and has at least three factors, the product of (a + 2) × B contains at least three factors, so it must be a composite number
Is the product of 98 2 + 1 and the product of 98 2 + 3 prime or composite?
The product of 98 2 + 1 is a composite number, and the product of 98 2 + 3 is a prime number
What is the difference between the product of the largest two-bit prime minus the smallest sum and the smallest two-bit prime?
The largest two prime number is 97
The smallest sum is 4
The smallest two digit prime is 11
Therefore, the difference is 97-4 × 11 = 53
The product of the reciprocal of the minimum prime number and the reciprocal of the minimum composite number is______ ．
12 × 14 = 18, so the answer is: 18
The reciprocal of the sum of the smallest composite number and the smallest prime number is ()
The minimum prime is 2 and the minimum sum is 4
The sum is 6
The countdown is 1 / 6
The reciprocal of the sum of the smallest composite number and the smallest prime number is (1 / 6)
Have a good time:)
The reciprocal of () is the smallest prime number, and the reciprocal of () is the smallest composite number
The reciprocal of (1 / 2) is the smallest prime number, and the reciprocal of (1 / 4) is the smallest composite number
What is prime 8 () + () = () - () 24 = () + () = () + ()
8 （2 ）+（ 5）＝（89 ）-（2 ）
24=（11）+（13）=（2）+（3）+（19）
RELATED INFORMATIONS
- 1. 100 = () + () = () + () (prime number)
- 2. The common factors of 12 and 18 are (), the largest of which is (). 12 and () are mutually prime numbers (fill in one possibility) The greatest common factor of 6 and 8 is () The greatest common factor of 17 and 51 is () The greatest common factor of 17 and 23 is () If M = 2 * 2 * 3 * 3, n = 2 * 3 * 5, then the greatest common factor of M and N is () Two, three, four and five can form a pair of Coprime numbers If there is a two digit number whose two digits are combined and prime to each other, the minimum of the two digits is () It is known that M = 2 * 3 * A and N = 2 * 7 * A. if the greatest common factor of M and N is 10, then a = () Two numbers that become coprime () Use a number to divide 32 and 28 exactly. The maximum number is ()
- 3. If the least common multiple of two prime numbers is 21, then the two prime numbers are () and (), respectively
- 4. Point out which of the following groups of numbers are coprime (1) 3 and 4; (2) 4 and 6; (3) 6 and 1; (4) 15 and 16; (5) 18 and 20; (6) 19 and 24; (7) 24 and 25; (8) 49 and 50 Come on, I'll give you a reward!
- 5. Put the proper prime number in the brackets 8 = （ ）＋ （ ﹚ 12 = ﹙ ﹚＋ ﹙ ﹚＋ ﹙ ﹚ 15 = ﹙ ﹚＋﹙ ﹚ 18 = ﹙ ﹚＋﹙ ﹚＋﹙ ﹚ If you think about it, the sum of the maximum factor and the minimum multiple of a number is 62. This number is 62_______
- 6. Which primes multiply the following integrals? (three primes) 42,50,63
- 7. The sum of two prime numbers is 40. What is the maximum product of the two prime numbers?
- 8. The sum of two prime numbers is 60. What is the maximum product of the two prime numbers?
- 9. Divide 406 into the sum of two prime numbers and find the minimum value of their product
- 10. The sum of three prime numbers is 52, and the product of them is the largest______ ．
- 11. If a and B are prime numbers, then M = a * B must be a composite number Is that right
- 12. 21 / 17 × (3 / 8-0.75) + 151 / 12 ÷ 17 / 21 the known natural number a has only two divisors, then 5A has at most three divisors List the formulas
- 13. There are three prime numbers. The sum of the three of them is 18. The product of the three of them is 78. What are they?
- 14. Which two primes can 48 be divided into 48 ＝（ ）＋（ ）＝（ ）＋（ ）＝（ ）＋ （ ） ＝（ ）＋（ ) ==（ ）
- 15. In prime numbers within 30, plus 2 is still prime
- 16. The product of two primes is 145 and the sum is 34. What is the larger of the two primes? Just answer, not use what you say
- 17. Decomposition prime 7,11,13,17,19,23,
- 18. There are () different ways to write 40 as the sum of two primes A. 2B. 3C. 4D. 5
- 19. The difference between two prime numbers is 2, and the product is 35. What are these two prime numbers
- 20. It is known that the product of two inner terms in a proportion is the smallest prime number, one outer term is 6 / 7, and the other outer term is () How much?