Put m=1
2^4=16
16-1=15
15 is divisible on 15...
Answer is yes......(2^4m)-1 is divisible on 15.....
–
Shahzad Saleem
·
12 months ago

Log in to reply

@Shahzad Saleem
–
You did not prove it, you just checked a case. Checking a case that does not represent all other cases is not a proof.
–
Anupam Nayak
·
11 months, 2 weeks ago

## Comments

Sort by:

TopNewest2^4 = 1 (mod 15) or, 2^4m = 1 (mod 15) or, 2^4m -1 = 0 (mod 15)

And it's proved. – Mahadi Hasan · 11 months ago

Log in to reply

Put m=1 2^4=16 16-1=15 15 is divisible on 15... Answer is yes......(2^4m)-1 is divisible on 15..... – Shahzad Saleem · 12 months ago

Log in to reply

– Anupam Nayak · 11 months, 2 weeks ago

You did not prove it, you just checked a case. Checking a case that does not represent all other cases is not a proof.Log in to reply