Evaluate the determinant of $\left|\begin{array}{cc}9 & 0 \\ 8 & -8\end{array}\right|$.
\[
\left|\begin{array}{cc}
9 & 0 \\
8 & -8
\end{array}\right|=
\]
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Final Answer: The determinant of the matrix is $\boxed{-72}$

Steps

Step 1 ：Given the matrix $\left|\begin{array}{cc}9 & 0 \ 8 & -8\end{array}\right|$

Step 2 ：The determinant of a 2x2 matrix $\left|\begin{array}{cc}a & b \ c & d\end{array}\right|$ is calculated as $ad - bc$

Step 3 ：Substitute a = 9, b = 0, c = 8, d = -8 into the formula

Step 4 ：The determinant is calculated as $ (9*-8) - (0*8) $

Step 5 ：Simplify to get the determinant as -72

Step 6 ：Final Answer: The determinant of the matrix is $\boxed{-72}$