Question

Correct ?
Which polynomial is prime?
A. 4x2 - 17x + 15
B. 4x2 + 13x
C. 8x2 + 7x - 16
D. x2 - 4

B.

Answer 1

Prime would mean it will not factor over some set, I assume the set of Rational numbers.

B does factor: 4x2 + 13x = x ( 4x + 13) so look again.

Answer 2

A. i think

Answer 3

That was my next choice but 4x^2 - 17x + 15 = (x - 3) (4x - 5) so it's something else.

Answer 4

D.

Answer 5

x^2 - 4 = (x) ^2 - (2) ^2 which is in the pattern for factoring the difference of two squares so that's not it.

Answer 6

C.

Answer 7

Yes. It has irrational roots.