Problem $2$: Given the matrix

$A=\left[\begin{array}{ccc}2& 4& 1\\ 6& 7& 2\\ 3& 5& 9\end{array}\right]$

provide the commands needed to do the following. Demonstrate that they work.

$($a$)$ assign the last element in the second row of $A$ to a scalar called $z$

$($b$)$ assign the first row of $A$ to a vector called $x1$

$($c$)$ assign the last $2$ rows of $A$ to an array called $y$

$($d$)$ assign the last $2$ columns of the last $2$ rows of $A$ to an array called $y1$