Practicing Success
If $P=\left[\begin{array}{r}-1 \\ 2 \\ 1\end{array}\right]$ and $Q=\left[\begin{array}{lll}2 & -4 & 1\end{array}\right]$ are two matrices, then $(PQ)'$ will be: |
$\left[\begin{array}{ccc}4 & 5 & 7 \\ -3 & -3 & 0 \\ 0 & -3 & -2\end{array}\right]$ $\left[\begin{array}{rrr}-2 & 4 & 2 \\ 4 & -8 & -4 \\ -1 & 2 & 1\end{array}\right]$ $\left[\begin{array}{rrr}5 & 5 & 2 \\ 7 & 6 & 7 \\ -9 & -7 & 0\end{array}\right]$ $\left[\begin{array}{rrr}-2 & 4 & 8 \\ 7 & 5 & 7 \\ -8 & -2 & 6\end{array}\right]$ |
$\left[\begin{array}{rrr}-2 & 4 & 2 \\ 4 & -8 & -4 \\ -1 & 2 & 1\end{array}\right]$ |
The correct answer is Option (2) → $\left[\begin{array}{rrr}-2 & 4 & 2 \\ 4 & -8 & -4 \\ -1 & 2 & 1\end{array}\right]$ |