Which polynomials are prime? check all that apply. 2x2+ 7x + 1 5x2 – 10x + 5 3x2 + 8 4x2 – 25 x2 + 36

The correct answer would be 2x2+ 7x + 1, 3x2 + 8    and x2 + 36. These polynomials cannot be reduced to a lower degree where the factors are integers so they should be prime. The factors are as follows:

2x2+ 7x + 1             -0.1492189406 and -3.350781059
5x2 – 10x + 5         1 and 1
3x2 + 8                     1.632993162i and - 1.632993162i
4x2 – 25                  5/2 and -5/2
x2 + 36                    6i and -6i

Ithink the answer is last one.