Use the matrix capabilities of a graphing utility to find AB,if possible. $$A = \left[ \begin{array} { c c }
4 & - 5 \
- 4 & 2 \
- 3 & - 9 \
- 5 & 8
\end{array} \right] , B = \left[ \begin{array} { c c c c }
- 1 & - 9 & 8 & - 7 \
- 9 & - 1 & - 1 & 9
\end{array} \right]$$
A) $$\left[ \begin{array} { c }
41 \
34 \
- 32 \
107
\end{array} \right]$$
B) $$\left[ \begin{array} { c c c c }
41 & - 31 & 37 & - 73 \
- 14 & 34 & - 34 & 46 \
84 & 36 & - 15 & - 60 \
- 67 & 37 & - 48 & 107
\end{array} \right]$$
C) $$\left[ \begin{array} { c c c c }
- 49 & - 41 & 27 & 17 \
22 & 38 & - 30 & 10 \
- 78 & 18 & - 33 & 102 \
77 & 53 & - 32 & - 37
\end{array} \right]$$
D)not possible
E) $$\left[ \begin{array} { c c c c }
41 & - 14 & 84 & - 67 \
- 31 & 34 & 36 & 37 \
37 & - 34 & - 15 & - 48 \
- 73 & 46 & - 60 & 107
\end{array} \right]$$

Question

Use the matrix capabilities of a graphing utility to find AB,if possible. $$A = \left[ \begin{array} { c c } 
4 & - 5 \
- 4 & 2 \
- 3 & - 9 \
- 5 & 8
\end{array} \right] , B = \left[ \begin{array} { c c c c } 
- 1 & - 9 & 8 & - 7 \
- 9 & - 1 & - 1 & 9
\end{array} \right]$$
A) $$\left[ \begin{array} { c } 
41 \
34 \
- 32 \
107
\end{array} \right]$$
B) $$\left[ \begin{array} { c c c c } 
41 & - 31 & 37 & - 73 \
- 14 & 34 & - 34 & 46 \
84 & 36 & - 15 & - 60 \
- 67 & 37 & - 48 & 107
\end{array} \right]$$
C) $$\left[ \begin{array} { c c c c } 
- 49 & - 41 & 27 & 17 \
22 & 38 & - 30 & 10 \
- 78 & 18 & - 33 & 102 \
77 & 53 & - 32 & - 37
\end{array} \right]$$
D)not possible
E) $$\left[ \begin{array} { c c c c } 
41 & - 14 & 84 & - 67 \
- 31 & 34 & 36 & 37 \
37 & - 34 & - 15 & - 48 \
- 73 & 46 & - 60 & 107
\end{array} \right]$$

Quizplus · Accepted Answer

Matrix multiplication is possible when the number of columns in the first matrix matches the number of rows in the second matrix. Here, matrix A is a 4x2 matrix and matrix B is a 2x4 matrix, so their product will be a 4x4 matrix. The correct answer must be a 4x4 matrix, which eliminates options A, D, and E. Option B is the only 4x4 matrix, making it the correct choice.

Use the Matrix Capabilities of a Graphing Utility to Find