The set of positive integers are example of ?

How do you use the elimination method for this question? explain, because i really want to understand!

Consider the polynomials given below. p(x) = x4 + 3x3 + 2x2 – x + 2 q(x) = (x3 + 2x2 + 3)(x2 – 2) determine the operation that results in the simplified expression below. 35 + x4 – 573 - 3x2 + x - 8 a. p+q b. pq c.q-p d. p-q

Acertain volume of water contains 100000 hydrogen atoms and 50,000 oxygen atoms how many hydrogen atoms are in a volume of water containing 4 million oxygen atoms