is really the only way of checking which number is divisble by 7 is by modular arithematics?
hfc="highest common factor"=gcd="greatest common divisor"loop quantum gravity said:can you tell me what hfc means?
I have no idea what you mean.loop quantum gravity said:and by modulo arithematics i mean that i divise the options of a number which is divisble by 7, and i got a blazing shock if ofcourse my way is right, it could be wrong.
But that equality holds for gcd as well...shmoe it cannot be that hfc is the same as gcd, at least in a page where iv'e seen a proof that hfc(a,b)=hfc(a,a-b).
and? gcd(a,b)=gcd(a,a-b) too. greatest common divisor, highest common factor, greatest common factor, highest common divisor, I've seen all these terms used in various number theory books (listed in roughly descending order of frequency) to mean exactly the same thing.loop quantum gravity said:shmoe it cannot be that hfc is the same as gcd, at least in a page where iv'e seen a proof that hfc(a,b)=hfc(a,a-b).
Just google "divisibility tests for 7" or some variation. There's little point in me going through them looking for tests that may be the same as yours given that I have no clue what I would be looking for.loop quantum gravity said:and about the test for divisibility, i'm not sure if it's genuine, but i welcome you if you can provide a link to these tests because i might as well just did something which is already known and not new at all.