Question

Is -7 and 3 is coprime number? it is necessary that HCF of a pair no. is 1 can't it be -1

Answer 1

neagative no's are only get in the category of real no .other than that they dont come in any other category.but 7 and 3 are coprime .if hcf of two numbers is 1.that means they are co prime .

and hcf of any 2 numbers can't be in negative.

Answer 2

$\tt{QUESTION}$ Are (-7) and 3 co-primes ?

$\tt{ANSWER}$ Yes !

$\tt{REASON}$ Two numbers are said to be co-primes only if they don't have any other common factor other than 1. These numbers don't have any other common factor other than 1. Thus, they are co-primes.

$\tt{QUESTION}$ Can the HCF of two numbers be (-1) ?

$\tt{ANSWER}$ No !

$\tt{REASON}$ The HCF can only be a positive number. This is because the HCF is the common factor. Numbers like 12 and 15 aren't negative, and thus, their factors also can't be negative. Thus, the HCF should only be positive.