If P(x) is a polynomial in x for which P(3)=0, then..?

Question

a) x-3 is a factor of P(x)
b) x+3 is a factor of P(x)
c) 3x is a factor of P(x)
d) x^3 is a factor of P(x)

Answer 1

The Remainder Theorem shows that (a) is the answer.