Question

I have a practice problem for my prep guide that I need answered, this is my answer *provided in the pic* but I’m not sure if I am correct. I just need someone to explain and answer it so that I know I’m right or wrong

Answer 1

The product of P and Q will give:

`PQ=\mleft[\begin{array}{ccc}-17 \\ -3 \\ -37 \\ 49\end{array}\mright]`

Step-by-step explanation:

Given the following matrices:

`\mleft[\begin{array}{ccc}1\text{ 2} \\ 3\text{ 0} \\ 5\text{ 4} \\ -1\text{ -6}\end{array}\mright]\text{and }\mleft[\begin{array}{ccc}-1 \\ -8\end{array}\mright]`

Taking the product of both matrices. We will multiply the rows of matrix P with the column matrix Q shown.

`\begin{gathered} PQ=\mleft[\begin{array}{ccc}(1*-1)+(2*-8) \\ (3*-1)+(0*-8) \\ (5*-1)+(4*-8) \\ (-1*-1)+(-6*-8)\end{array}\mright] \\ PQ=\mleft[\begin{array}{ccc}-1-16 \\ -3+0 \\ -5-32 \\ 1+48\end{array}\mright] \\ \\ PQ=\mleft[\begin{array}{ccc}-17 \\ -3 \\ -37 \\ 49\end{array}\mright] \\ \end{gathered}`