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What is prime, what is composite, what is least common multiple and greatest common multiple
Because 0 is usually regarded as a natural number in the world, and 0 is also regarded as a natural number in the national standard, the prime number and composite number are generally defined in the range of positive integers (0 is the multiple of all positive integers, so it is meaningless to study it, and 0 cannot be used as a divisor). Prime number: except 1 and itself, the number with no other factor is prime number, 1 is neither prime nor composite. A common divisor is also called a common divisor. If a number is a divisor of several numbers at the same time, it is called their "common divisor"; the largest of the common divisors is called the "greatest common divisor". For example, 2, - 2,7, - 7,14, - 14 are 28,42, The common divisor of 70; 14 is their greatest common divisor. There is no least common divisor. The least common multiple: if a number is a multiple of several numbers at the same time, it is called their "common multiple"; the smallest of positive common multiple is called "the least common multiple". For example, 12, - 12,24, - 24 are all common multiples of 2,4,6; 12 is their least common multiple
The difference between a number minus the product of the minimum prime number and the minimum composite number is exactly the greatest common factor of 51 and 68. What is the number
We need it now
The greatest common factor of 51 and 68 is 17
The minimum prime is 2
The minimum sum is 4
Then the number is: 17 + 2 × 4 = 25
In positive integers, what is the sum of the smallest prime number and the smallest composite number?
The smallest prime number is 2, the smallest composite number is 4, 2 + 4 = 6; a: the sum of them is 6
A prime number and a composite number cannot form a coprime number______ ．
According to the meaning of prime number, composite number and coprime number, if a composite number is a multiple of a prime number, then the composite number and the prime number are not coprime, such as 3 and 6. If a prime number and a composite number have no multiple relationship, then two numbers are coprime, such as 3 and 8. Therefore, a prime number and a composite number cannot form a coprime number
Two composite numbers must not be coprime numbers______ (judge right or wrong)
According to the definition of Coprime number, two composite numbers may also be coprime numbers, such as 8 and 9
1 is neither prime nor composite. It is coprime with any natural number. Is that right?
Wrong
reason:
Two numbers with only one common factor are called coprime numbers
It should be changed to: "1 is neither prime nor composite. It is coprime with any natural number that is not zero."
Among the seven natural numbers, there are () pairs of Coprime numbers composed of a prime number and a composite number
34 45 47 56 67
5 pairs
Prime number () and composite number () are coprime numbers in 5, 9, 11 and 14
5 and 9
5 and 14
11 and 9
11 and 14
These groups all meet the requirements
If you don't understand, you can say
The concept of factor and multiple
A factor is an integer after a number is divided by 2, 3, and 5, that is to say, 2, 3, and 5 are the factors of the number. For example, 24 divided by 3 equals 8, so 3 is the factor of 24. A multiple is a number divided by another number, for example, 10 divided by 5 equals 2, so 10 is a multiple of 5
Kneel down to find the meaning of factors and multiples
A number is the product of those numbers
For example, 4 2 times 2 6 2 times 3 2 and 3 are all factors of 6
It's a positive integer multiple of this number
Six is a multiple of two or three
RELATED INFORMATIONS
- 1. What are factors and multiples
- 2. Using the smallest prime number, the smallest odd number and the smallest composite number in the natural number to form a minimum three digit number is______ ．
- 3. Which are prime numbers, which are composite numbers, which are even numbers and which are odd numbers in 49,51,12,37,1,0.5,85
- 4. If the least common multiple of two integers is 140, the greatest common divisor is 4, and the decimal cannot divide the large number, then the two integers If the least common multiple of two integers is 140, the greatest common divisor is 4, and the decimal cannot divide the large number, then the two integers are ()
- 5. The two numbers a and B only contain 2 and 3 prime factors. The number a has 21 divisors and the number B has 10 divisors. Their greatest common divisor is 18. How many are these two numbers
- 6. The difference between the least common multiple and the greatest common multiple of a and B is 20, which is equal to the sum of the two numbers
- 7. The minimum multiple of a number is 36, and the divisor of the number is
- 8. The divisor of 16 is______ Among these divisors, four divisors are selected to form at least two proportions______ ．
- 9. What are the divisors of 36? Find four numbers to form a proportion ()
- 10. Choose four numbers from the divisors of 24 to make up the proportion
- 11. If the greatest common divisor of two numbers is 42, the least common multiple is 2940, and the sum of the two numbers is 714, then the two numbers are______ ．
- 12. The greatest common factor of two numbers is 8, the least common multiple is 96, one of which is 32, find the other
- 13. A divided by B equals 9. The greatest common factor of a and B is () and the least common multiple is ()
- 14. The greatest common factor of two one digit numbers is 1, and the least common multiple is 72
- 15. The greatest common divisor of two numbers is 1, and the least common multiple is 72______ And______ Or______ And______ ．
- 16. Least common multiple and greatest common divisor of decimals and fractions 9.6 how to find the least common multiple of 16 18? The simpler the better
- 17. What is the greatest common divisor of 18 and 30______ The least common multiple is______ ．
- 18. The greatest common divisor of a and B is 8, and the least common multiple is 560. One of them is 80, and what is the other? (to calculate the formula)
- 19. If a is a multiple of B, then the least common multiple of a and B is______ ．
- 20. Write the greatest common factor of numerator and denominator One third () four sixths () six twelfth () Twenty one out of 49 () six out of 48 () twenty seven out of 81 ()