Questions: Find the following matrix product, if it exists.
[
left[beginarrayrr
-3 9
-5 -7
endarrayright]left[beginarrayl
8
7
endarrayright]
]
Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. The matrix product is
B. The product does not exist.
Transcript text: Find the following matrix product, if it exists.
\[
\left[\begin{array}{rr}
-3 & 9 \\
-5 & -7
\end{array}\right]\left[\begin{array}{l}
8 \\
7
\end{array}\right]
\]
Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. $\left[\begin{array}{rr}-3 & 9 \\ -5 & -7\end{array}\right]\left[\begin{array}{l}8 \\ 7\end{array}\right]=\square$ (Simplify your answer.)
B. The product does not exist.
Solution
Solution Steps
Step 1: Check for Compatibility
To multiply two matrices, the number of columns in the first matrix must equal the number of rows in the second matrix. Here, Matrix A has 2 columns and Matrix B has 2 rows, which are compatible for multiplication.
Step 2: Initialize the Product Matrix
The product matrix C will have dimensions 2x1.
Step 3: Calculate the Product
For each element \(c_{ij}\) in matrix \(C\), calculate the sum of the products of the corresponding elements from the \(i\)th row of \(A\) and the \(j\)th column of \(B\).
Formally, \(c_{ij} = \sum_{k=1}^{n} a_{ik}b_{kj}\) for all \(i = 1, 2, ..., m\) and \(j = 1, 2, ..., p\).
Where \(n\) is the number of columns in \(A\) (or rows in \(B\)), \(m\) is the number of rows in \(A\), and \(p\) is the number of columns in \(B\).