des5kamlyovMizu des5kamlyovMizu 23-02-2017 Mathematics contestada Which is NOT a polynomial? A. 4/x^4 + 3/x^3− 2/x^2 −1 B. x^5 − 5x^4 + 4x^3 −3x^2 C. 3x^2 + 5x^4 + 2x − 12 D. x^3− 7x^2 + 9x −20