There are number of positive divisors of , number of positive divisors of .
The positive divisors of that are not divisors of are .
Hoping there's a formula and you're not actually supposed to go over all possible numbers...
Any help appreciated.
First, to tell you that I was not quite sure what you meant with what you defined to be. In other words, is confusing and threw me off, so I do not understand what you mean when you say "the number of divisors of ". Is it the number of divisors that overlap for the two? Is it the sum of the number of divisors, not taking into regard the case of overlap?
Second, to clarify what it was I meant. You did ask me to, didn't you?
English is my first language. I just don't have a very wide vocabulary when it comes to mathematics.You did not read my reply? It says clearly what equals.
Do you have difficulty translating Enghish?
But sure, I'll look over your post again for hints to what I might not be seeing clearly.
Any positive integer can be factors as powers of primes.
look at the exponents:
Then add one to each exponent and multiply: .
So there are 27 divisors of 900.
, so .
There 12 divisors of 72.
The greatest common divisor: so common divisors of both 72 and 900.
Thus there are divisors of 900 that are not divisors of 72.