Find AB and BA $A = \left[ \begin{array} { l l l } 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array} \right]$

Multiple Choice

Find AB and BA.
- $A = \left[ \begin{array} { l l l } 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array} \right]$ and $B = \left[ \begin{array} { r r r } 1 & 1 & - 5 \\ 8 & - 9 & - 5 \\ - 1 & 4 & 5 \end{array} \right]$

A) $A B = \left[ \begin{array} { r r r } 1 & 1 & - 5 \\ 8 & - 9 & - 5 \\ - 1 & 4 & 5 \end{array} \right] ; B A = \left[ \begin{array} { r r r } 1 & 8 & - 1 \\ 1 & - 9 & 4 \\ - 5 & - 5 & 5 \end{array} \right]$

B) $A B = \left[ \begin{array} { r r r } 1 & 0 & 0 \\ 0 & - 9 & 0 \\ 0 & 0 & 5 \end{array} \right] ; B A = \left[ \begin{array} { r r r } 1 & 0 & 0 \\ 0 & - 9 & 0 \\ 0 & 0 & 5 \end{array} \right]$

C) $A B = \left[ \begin{array} { l l l } 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array} \right] ; B A = \left[ \begin{array} { l l l } 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array} \right]$

D) $A B = \left[ \begin{array} { r r r } 1 & 1 & - 5 \\ 8 & - 9 & - 5 \\ - 1 & 4 & 5 \end{array} \right] ; B A = \left[ \begin{array} { r r r } 1 & 1 & - 5 \\ 8 & - 9 & - 5 \\ - 1 & 4 & 5 \end{array} \right]$