Answer
$\begin{bmatrix} -15 & -16 & 3 \\-1 & 0 & 9 \\7 & 6 & 12 \end{bmatrix} $
Work Step by Step
Consider $A=\begin{bmatrix} -2 & -3 & -4\\ 2&-1&0\\4 &-2&3 \end{bmatrix} $ and $B=\begin{bmatrix} 0 & 1 & 4 \\ 1 & 2 & -1\\ 3& 2& -2\end{bmatrix} $
Since, the dimensions of both matrix $A$ and $B$ is $3 \times 3$ .This follows that the number of columns of matrix-$A$ will be same as the number of rows of the matrix-$B$ and so, we can take their product $AB$.
$AB=\begin{bmatrix} -2 & -3 & -4\\ 2&-1&0\\4 &-2&3 \end{bmatrix} \begin{bmatrix} 0 & 1 & 4 \\ 1 & 2 & -1\\ 3& 2& -2\end{bmatrix}\\=\begin{bmatrix} 0-3-12 & -2-6-8& -8+3+8 \\0-1+0 & 2-2+0 &8+1+0\\0-2+9&4-4+6&16+2-6 \end{bmatrix}$
$ \\ =\begin{bmatrix} -15 & -16 & 3 \\-1 & 0 & 9 \\7 & 6 & 12 \end{bmatrix} $
