Which of the following is a polynomial?

C

Step-by-step explanation:

Polynomials should consist of only non-negative integer powers of x. Thus B and D are definitely not. It might be possible to simplify A into something that looks like a polynomial, but it’s a bit difficult. If you just need to choose one, then C is definitely a good choice.

My incomplete attempt of factorizing A:

20

step-by-step explanation:

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.