If x – 1, x + 2 and x + 1 are all factors of a polynomial P(x) of degree 3, which of the following must also be a
factor of P(x)?
I) x^2+ 3x + 2
II) x^2– 1
III) x^2+ x – 2
A) III only
B) II only
C) I only
D) All three are factors

Question

If x – 1, x + 2 and x + 1 are all factors of a polynomial P(x) of degree 3, which of the following must also be a
factor of P(x)?
I) x^2+ 3x + 2
II) x^2– 1
III) x^2+ x – 2
A) III only
B) II only
C) I only
D) All three are factors

hba · Answer

@dpaInc

anonymous · Answer

HINT:  since 2, 3, 5 are factors of 30, then:
2*3 = 6
2*5 = 10
3*5 = 15
are also factors of 30.....

anonymous · Answer

in other words, since (x-1), (x+2), (x+1) are factors of P(x), then:
(x-1)(x+2) = ???
(x-1)(x+1) = ???
(x+1)(x+2) = ??? 
are also factors of P(x)....