Question

Which expression is a polynomial?

A. 9x^7y^-3z
B. 4x^3-2x^2+5x-6+1/x
C. -13
D. 13^-2

Answer 1

I believe the answer is C.
A polynomial cannot contain a negative number raised to the power (eliminating A. and D.) and a polynomial cannot contain any division by a variable (eliminating B.)
C. is what I would consider a polynomial. It contains one term, and does not break any rules.

Answer 2

Option B. is the polynomial.

Explanation:

In this question we will simplify every option given

(A) 9x⁷y⁻³z =
`(9x^(7)z )/(y^3)` It is a monomial.

(B) 4x³-2x²+5x-6+1/x This expression has 5 terms so it's a polynomial.

(C) -13 one term means monomial.

(D) 13⁻² =
`(1)/(13^2)` one term means monomial.

Therefore, Option B. is the polynomial.