2018 AMC 12A Problems/Problem 21
Problem
Which of the following polynomials has the greatest real root?
Solution
We can see that our real solution has to lie in the open interval . From there, note that
if a, b are odd positive integers so
, so hence it can only either be B or E(as all of the other polynomials will be larger than the polynomial B). Finally, we can see that plugging in the root of
into B gives a negative, and so the answer is
. (cpma213)