Find the product.

[tex]\[
\begin{array}{c}
{\left[\begin{array}{cc}
4 & -2 \\
-3 & 5 \\
9 & 10 \\
6 & 11
\end{array}\right]\left[\begin{array}{c}
7 \\
-4
\end{array}\right]} \\
\end{array}
\][/tex]



Answer :

To solve the problem of finding the product of the given matrix and vector, we will perform matrix multiplication. Here are the detailed steps:

We are given a matrix:
[tex]\[ \begin{bmatrix} 4 & -2 \\ -3 & 5 \\ 9 & 10 \\ 6 & 11 \end{bmatrix} \][/tex]
and a vector:
[tex]\[ \begin{bmatrix} 7 \\ -4 \end{bmatrix} \][/tex]

We need to find the product of the matrix and the vector. The result will be a new vector obtained by performing the dot product of each row of the matrix with the vector.

Step-by-step, we will calculate each element of the resulting vector:

1. First element:
[tex]\[ (4 \times 7) + (-2 \times -4) = 28 + 8 = 36 \][/tex]

2. Second element:
[tex]\[ (-3 \times 7) + (5 \times -4) = -21 - 20 = -41 \][/tex]

3. Third element:
[tex]\[ (9 \times 7) + (10 \times -4) = 63 - 40 = 23 \][/tex]

4. Fourth element:
[tex]\[ (6 \times 7) + (11 \times -4) = 42 - 44 = -2 \][/tex]

Thus, the product of the given matrix and vector is:
[tex]\[ \begin{bmatrix} 36 \\ -41 \\ 23 \\ -2 \end{bmatrix} \][/tex]

So the final result is:
[tex]\[ \begin{array}{c} {\left[\begin{array}{cc} 4 & -2 \\ -3 & 5 \\ 9 & 10 \\ 6 & 11 \end{array}\right]\left[\begin{array}{c} 7 \\ -4 \end{array}\right]} = \\ {[[\begin{array}{c} 36 \\ -41 \\ 23 \\ -2 \end{array}]]} \end{array} \][/tex]