Compute the product, if possible.
$\left[ \begin{array} { l l }
2 & - 4 \
2 & - 4
\end{array} \right] \cdot \left[ \begin{array} { l l }
4 & - 4 \
1 & - 7
\end{array} \right]$

A) $\left[ \begin{array} { l l }
4 & 20 \
4 & 20
\end{array} \right]$
B) $\left[ \begin{array} { l l }
5 & 19 \
4 & 20
\end{array} \right]$
C) $\left[ \begin{array} { l l }
5 & 19 \
2 & 22
\end{array} \right]$
D) $\left[ \begin{array} { l l }
4 & - 20 \
2 & - 22
\end{array} \right]$
E) Undefined

Question

Compute the product, if possible.  
  $\left[ \begin{array} { l l } 
2 & - 4 \
2 & - 4
\end{array} \right] \cdot \left[ \begin{array} { l l } 
4 & - 4 \
1 & - 7
\end{array} \right]$  
 
A) $\left[ \begin{array} { l l } 
4 & 20 \
4 & 20
\end{array} \right]$
B) $\left[ \begin{array} { l l } 
5 & 19 \
4 & 20
\end{array} \right]$
C)   $\left[ \begin{array} { l l } 
5 & 19 \
2 & 22
\end{array} \right]$
D) $\left[ \begin{array} { l l } 
4 & - 20 \
2 & - 22
\end{array} \right]$
E) Undefined

Quizplus · Accepted Answer

The product of the two matrices is calculated by multiplying rows by columns. For the first matrix, each element in the first row is multiplied by the corresponding element in the first column of the second matrix, and the results are added together. This process is repeated for each combination of rows and columns. The correct product is $\left[ \begin{array} { l l } 4 & 20 \ 4 & 20 \end{array} \right]$, which matches option A.

Compute the Product, If Possible [2−42−4]⋅[4−41−7]\left[ \begin{array} { l l } 2 & - 4 \\2 & - 4\end{array} \right] \cdot \left[ \begin{array} { l l } 4 & - 4 \\1 & - 7\end{array} \right][22​−4−4​]⋅[41​−4−7​]

Compute the Product, If Possible $\left[ \begin{array} { l l } 2 & - 4 \\2 & - 4\end{array} \right] \cdot \left[ \begin{array} { l l } 4 & - 4 \\1 & - 7\end{array} \right]$