Answer
NOT a factor
Work Step by Step
Equating the given expression, $
x-4
,$ to zero and then solving for $x,$ then
\begin{align*}
x-4&=0
\\
x-4+4&=0+4
\\
x&=4
.\end{align*}
Using $
4
$ in the synthetic division below, then the remainder is $
336
$ (bottom-right number).
Since the remainder is NOT zero, then $
x-4
$ is NOT a factor of $3x^3+10x^2-x-12$.
