91Ó°ÊÓ

Perform the indicated matrix operations.8.

$5\left[\begin{array}{l}\begin{array}{ccc}−2& 4& 5\end{array}\\ \begin{array}{ccc}0& −4& 7\end{array}\end{array}\right]$

Find each product, if possible.

$\left[\begin{array}{ccc}5& −2& −1\\ 8& 0& 3\end{array}\right]â‹\dots \left[\begin{array}{cc}−4& 2\\ 1& 0\end{array}\right]$

Use Cramer’s Rule to solve each system of equations.

$a+9b-2c=2$

$-a-3b+4c=1$

$2a+3b-6c=-5$

Use Cramer’s rule to solve each system of equations.

8.

$\begin{array}{l}\mathbf{3}\mathbf{x}−\mathbf{2}\mathbf{y}=\mathbf{7}\\ \mathbf{4}\mathbf{x}−\mathbf{y}=\mathbf{6}\end{array}$

Use matrices A, B, and C to find the following.

$A=\left[\begin{array}{cc}2& 3\\ 5& 6\end{array}\right],B=\left[\begin{array}{cc}−1& 7\\ 0& 4\end{array}\right],C=\left[\begin{array}{cc}9& −4\\ −6& 5\end{array}\right]$

$A+B+C$

Find the inverse of each matrix, if it exists.

$\left[\begin{array}{cc}\mathbf{-}\mathbf{5}& \mathbf{1}\\ \mathbf{7}& \mathbf{4}\end{array}\right]$

For exercises 7-10, use the rectangle at the right

Find the coordinates of the image after a dilation by a scale factor of 3.

Find each product, if possible.

$\left[\begin{array}{cc}4& −1\\ 3& 5\end{array}\right]â‹\dots \left[\begin{array}{c}7\\ 4\end{array}\right]$

Find the value of each determinant.

9.$\left|\begin{array}{cc}0& 8\\ 5& 9\\ & \end{array}\right|$

Find each product, if possible.9.

$\left[\begin{array}{ccc}4& 0& −8\\ 7& −2& 10\end{array}\right].\left[\begin{array}{cc}−1& 3\\ 6& 0\end{array}\right]$