Hi,
Need help with this problem;
Let a,b1,b2,....bn E Z, with (a,b1)=(a,b2)=(a,b3)=....=(a,bn)=1
Prove that
(a,b1b2....bn) = 1
Thanks
Hello htata123You need to consider the (unique) prime factorisation of $\displaystyle a$ and all the $\displaystyle b_i$, and then use the fact that $\displaystyle a$ does not have any prime factor in common with any of the $\displaystyle b_i$, and therefore neither with $\displaystyle \prod{b_i}$.
Grandad