Question

hey friends specially maths lover I have a question for u plz help me

1) if m is a natural no. then 5^m+9^2m always ends with ____.
2) 1/3+1/15+1/35+1/63+1/99= ____.
3) find all primes p and q such that p²+7pq+q² is the square of an integer.
4) for how many integer n, p=n^4+4n^3+3n^2-2n+7 is prime

these questions are of PRE-RMO practice test if u know then Plzz explain it in detail with each and every steps
if this instructions are followed by u then I will definitely mark u brainliest
PlZ don't spam
help me.....

Answer 1

answer of first question