Exercise 5

Compute the determinant by using the permutation expansion.

• (a)  $\begin{vmatrix}1&2&3\\ 4&5&6\\ 7&8&9\end{vmatrix}$     (b)  $\begin{vmatrix}2&2&1\\ 3&-1&0\\ -2&0&5\end{vmatrix}$