HELP PLEASE

SHOW ALL STEPS FOR BOTH PARTS & EXPLAIN A$)$ Two$-$port networks N$1$ and N$2$ are connected in parallel.

The parameters for each network are as follows:

$N1$:$Y_1=\left[\begin{array}{cc}1& -0\mathrm{.}5\\ -0\mathrm{.}5& 2\end{array}\right],N2$:$Y_2=\left[\begin{array}{cc}2& 0\\ 0& 1\end{array}\right].$ Find the $Y-$parameters

for the overall network $($total Y$-$parameters$).$

B$)$ Two$-$port networks N$1$ and N$2$ are connected in cascade.

The parameters for each network are as follows:

$N1$:$[ABCD{]}_1=\left[\begin{array}{cc}1& 2\\ 0\mathrm{.}5& 1\end{array}\right],N2$:$[ABCD{]}_2=\left[\begin{array}{cc}2& 1\\ 1& 2\end{array}\right].$ Find the total ABCD parameters$).$