What is the product of the matrices

[tex]\[
\left[\begin{array}{lll}0 & -1 & -4\end{array}\right]
\left[\begin{array}{c}-2 \\ 5 \\ -1\end{array}\right]
\][/tex]?

A. [tex]\(-1\)[/tex]

B. [tex]\(\left[\begin{array}{c}0 \\ -2 \\ -8\end{array}\right]\)[/tex]

C. [tex]\(\left[\begin{array}{lll}0 & -5 & 4\end{array}\right]\)[/tex]

D. [tex]\(\left[\begin{array}{ccc}0 & 2 & 8 \\ 0 & -5 & -20 \\ 0 & 1 & 4\end{array}\right]\)[/tex]



Answer :

To determine the product of the matrices [tex]\(\left[\begin{array}{lll}0 & -1 & -4\end{array}\right]\)[/tex] and [tex]\(\left[\begin{array}{c}-2 \\ 5 \\ -1\end{array}\right]\)[/tex], we follow the steps for matrix multiplication.

Given:
Matrix [tex]\( A = \left[ \begin{array}{ccc} 0 & -1 & -4 \end{array} \right] \)[/tex]
Matrix [tex]\( B = \left[ \begin{array}{c} -2 \\ 5 \\ -1 \end{array} \right] \)[/tex]

The product of these matrices can be computed as:

[tex]\[ A \cdot B = \left[ \begin{array}{ccc} 0 & -1 & -4 \end{array} \right] \cdot \left[ \begin{array}{c} -2 \\ 5 \\ -1 \end{array} \right] \][/tex]

To multiply them, you take the dot product of the row vector from matrix [tex]\( A \)[/tex] with the column vector from matrix [tex]\( B \)[/tex]:

[tex]\[ \left( 0 \times (-2) \right) + \left( -1 \times 5 \right) + \left( -4 \times (-1) \right) \][/tex]

Calculating each term:

[tex]\[ 0 \cdot (-2) = 0 \][/tex]

[tex]\[ -1 \cdot 5 = -5 \][/tex]

[tex]\[ -4 \cdot (-1) = 4 \][/tex]

Now, add these results together:

[tex]\[ 0 + (-5) + 4 = -1 \][/tex]

Therefore, the product of the matrices is:

[tex]\[ -1 \][/tex]

So the answer is [tex]\(-1\)[/tex].