7. Systems of Equations & Matrices

What is the value of x if ?

Evaluate each determinant.

Evaluate each determinant in Exercises 1–10.

$\begin{vmatrix}-5 & -1 \\-2 & -7\end{vmatrix}$

Evaluate each determinant.

Evaluate each determinant in Exercises 1–10.$\begin{vmatrix}\frac{1}{2} & \frac{1}{2} \\\frac{1}{8} & - \frac{3}{4}\end{vmatrix}$

Evaluate each determinant.

Evaluate each determinant.

For Exercises 11–22, use Cramer's Rule to solve each system. $\begin{cases}12x + 3y = 15 \\2x - 3y = 13\end{cases}$

Evaluate each determinant.

For Exercises 11–22, use Cramer's Rule to solve each system. $\begin{cases}4x - 5y = 17 \\2x + 3y = 3\end{cases}$

For Exercises 11–22, use Cramer's Rule to solve each system. $\begin{cases}x + 2y = 3 \\3x - 4y = 4\end{cases}$

Find the cofactor of each element in the second row of each matrix.

Find the cofactor of each element in the second row of each matrix.

For Exercises 11–22, use Cramer's Rule to solve each system. $\begin{cases}3x - 4y = 4 \\2x + 2y = 12\end{cases}$

Evaluate each determinant.