Answer
See below.
Work Step by Step
a) The general form of a polynomial P of degree $n$ is:
$P=a_nx^n+a_{n-1}x^{n-1}++a_1x+a_0$
where $a_n\ne0$ and $a_i$ is a real number for $0\leq i\leq n$.
b) According to the factor theorem, a number $c$ is a zero if $(x-c)$ is a factor of $P$ or if $f(c)=0$.
