can anybody help me on this problem ...
i can show by Disproof by counterexample
for all integers n>= 1
suppose n^2 - 7n + 49 is prime
try n =1 then it is equal to 43, still prime
if n = 2 then 39, composite
n^2 - 7n + 49 is not a prime for some integer n>=1.
but for this problem i can not seem to express how it should be done..
thanks a lot so much.