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8 November, 03:48

Use the lists of factors to answer the question. Factors of 9: 1, 3, 9 Factors of 15: 1, 3, 5, 15 Factors of 21: 1, 3, 7, 21 Factors of 40: 1, 2, 4, 5, 8, 10, 20, 40 Which pairs of numbers are relatively prime? Check all that apply. 9 and 15 9 and 40 9 and 21 15 and 21 21 and 40

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  1. 8 November, 05:19
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    9 and 40

    21 and 40

    Step-by-step explanation:

    Factors of 9:

    1,3,9

    Factors of 15:

    1,3,5,15

    Factors of 21:

    1,3,7,21

    Factors of 40:

    1,2,4,5,8,10,20,40

    We have to find the pairs of numbers which are relatively prime.

    Relatively prime number: The numbers in which gcd 1 are called relative prime numbers.

    a. 9 and 15

    GCD (9,15) = 3

    9 and 15 are not relatively prime.

    b. 9 and 40

    GCD (9,40) = 1

    Hence, 9 and 40 are relatively prime.

    c. 9 and 21

    GCD (9,21) = 3

    9 and 21 are not relatively prime.

    d. 15 and 21

    GCD (15,21) = 3

    15 and 21 are not relatively prime.

    e. 21 and 40

    GCD (21,40) = 1

    21 and 40 are relatively prime.
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