Evaluate the expression.
$$\left[ \begin{array} { c }
- 5 \
- 1 \
5
\end{array} \right] \left( \left[ \begin{array} { l l }
9 & - 7
\end{array} \right] + \left[ \begin{array} { l l }
- 7 & - 8
\end{array} \right] \right)$$
A)
$\left[ \begin{array} { c } - 10 \ - 2 \ 10 \end{array} \right]$
B) $\left[ \begin{array} { c c } - 10 & 75 \ - 2 & 15 \ 10 & - 75 \end{array} \right]$
C) $\left[ \begin{array} { c c c } - 10 & - 2 & 10 \ 75 & 15 & - 75 \end{array} \right]$
D) $\left[ \begin{array} { c c c c } - 45 & 35 & 35 & 40 \ - 9 & 7 & 7 & 8 \ 45 & - 35 & - 35 & - 40 \end{array} \right]$
E) not possible

Question

Evaluate the expression.
$$\left[ \begin{array} { c } 
- 5 \
- 1 \
5
\end{array} \right] \left( \left[ \begin{array} { l l } 
9 & - 7
\end{array} \right] + \left[ \begin{array} { l l } 
- 7 & - 8
\end{array} \right] \right)$$
A)
$\left[ \begin{array} { c } - 10 \ - 2 \ 10 \end{array} \right]$
B) $\left[ \begin{array} { c c } - 10 & 75 \ - 2 & 15 \ 10 & - 75 \end{array} \right]$
C) $\left[ \begin{array} { c c c } - 10 & - 2 & 10 \ 75 & 15 & - 75 \end{array} \right]$
D) $\left[ \begin{array} { c c c c } - 45 & 35 & 35 & 40 \ - 9 & 7 & 7 & 8 \ 45 & - 35 & - 35 & - 40 \end{array} \right]$
E) not possible

Quizplus · Accepted Answer

First, add the two row matrices: $[9, -7] + [-7, -8] = [2, -15]$. Then, multiply the column matrix by the resulting row matrix: $\left[ \begin{array} { c } - 5 \ - 1 \ 5 \end{array} \right] \times \left[ \begin{array} { c c } 2 & -15 \end{array} \right] = \left[ \begin{array} { c c } - 10 & 75 \ - 2 & 15 \ 10 & - 75 \end{array} \right]$.

Evaluate the Expression A) [−10−210]\left[ \begin{array} { c } - 10 \\ - 2 \\ 10 \end{array} \right]​−10−210​​

Evaluate the Expression A) $\left[ \begin{array} { c } - 10 \\ - 2 \\ 10 \end{array} \right]$