Is there anybody who knows how to solve the following?
Qn1: Show that for any integer n ≥ 0, one has gcd( n!+1, (n+1)!+1 ) = 1
Qn2 :Why is it that the greatest common divisor of any two integers a,b∈Z is defined as the unique non-negative integer gcd(a,b)∈Z, where Z is ≥ 0 such that: {ar + bs ∈ Z : r,s∈Z} = gcd(a,b)*Z