Exercise 1

Find each determinant by performing one row operation.

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