\left[ 
\begin{array}{cc} 
1 & y_1 \\ 
1 & y_2 
\end{array} 
\right] 
\left[ 
\begin{array}{c} 
C(z) \\ A(z) 
\end{array} 
\right] 
=\left[ 
\begin{array}{c} 
k_1z+n_1 \\ k_2z+n_2 
\end{array} 
\right],\quad 
\left[ 
\begin{array}{ccc} 
1 & y_1 & y_1^2 \\ 
1 & y_2 & y_2^2 \\ 
1 & y_3 & y_3^2 
\end{array} 
\right] 
\left[ 
\begin{array}{c} 
E(z) \\ 
D(z) \\ 
B(z) 
\end{array} 
\right] 
=\left[ 
\begin{array}{c} 
a_1z^2+b_1z+c_1 \\ 
a_2z^2+b_2z+c_2 \\ 
a_3z^2+b_3z+c_3 
\end{array} 
\right]