Ernstfalld

2021-01-07

Find the product of the following matrices , if possible
$\left[\begin{array}{cc}6& -9\\ -5& 5\end{array}\right]\left[\begin{array}{c}-1\\ 6\end{array}\right]$
Select the correct choise below and , if necessary , fill in the answer box to complete your choise.
A)$\left[\begin{array}{cc}6& -9\\ -5& 5\end{array}\right]\left[\begin{array}{c}-1\\ 6\end{array}\right]$
B)The product is not defined

ottcomn

Step 1
First matrix is $2×2$ and second matrix is $2×1$
It is therefore possible to multiply
$\left[\begin{array}{cc}6& -9\\ -5& 5\end{array}\right]\left[\begin{array}{c}-1\\ 6\end{array}\right]$
Step 2
Next, matrix multiplication is used to multiply the matrices.
$\left[\begin{array}{cc}6& -9\\ -5& 5\end{array}\right]\left[\begin{array}{c}-1\\ 6\end{array}\right]$
$\left[\begin{array}{c}6\left(-1\right)+\left(-9\right)\left(6\right)\\ \left(-5\right)\left(-1\right)+5\left(6\right)\end{array}\right]$
$\left[\begin{array}{c}-6-54\\ 5+30\end{array}\right]=\left[\begin{array}{c}-60\\ 35\end{array}\right]$

Jeffrey Jordon