1. ## COMPUTE MATRIX

COMPUTE AB AND BA IF POSSIBLE

1 2 3 =A
-4 -2 5

1 2 1
-4 5 -2 =B
0 3 -1

2. Originally Posted by waterboy
COMPUTE AB AND BA IF POSSIBLE

1 2 3 =A
-4 -2 5

1 2 1
-4 5 -2 =B
0 3 -1
$A=\left[\begin{array}{ccc}1 & 2 & 3 \\ -4 & -2 & 5 \end{array}\right]$

$B=\left[\begin{array}{ccc}1 & 2 & 1 \\ -4 & 5 & 2 \\ 0 & 3 & -1 \end{array}\right]$

$AB=\left[\begin{array}{ccc}-7 & 21 & -6 \\ 4 & -3 & -5 \end{array}\right]$

BA is not possible because B is a 3 x 3 matrix and A is a 2 x 3, so we have a dimension mismatch.