Hi guys, I'm going to a math competition soon, and there are a few problems that have stumped both me and my teacher. I was wondering if any of you could help me out? Prove (a^2+b^2)/(a+b) >= sqrt(ab) for all real A and B. p(x)mod(x-19) = 99 p(x)mod(x-99) = 19 p(x)mod(x-19)(x-99) = ??? Suppose for an integer, n, there exists numbers 2n+1 and 3n+1 that are perfect squares. Prove that n cannot be prime. Thanks a ton for the help! I appreciate it.