old Math League competition. pls type the anss down

1-4. If x2 + xy + yz = 7 and x + y = 2, what is the value of xy?1-4.1-5. There are 5 positive integers less than 6, and 3 of these are factors1-5of 6; so 60% of the positive integers less than 6 are factors of 6.What is the smallest positive integer n > 1 for which fewer than1% of the positive integers less than n are factors of n?1-6. It can be proven that there are exactly three integral values of x for1-6.which 4* + 41993 + 419% is a perfect square (the square of an inte-ger). What are these three values of x?