\hsize 0pt
\vsize 0pt
\nopagenumbers
\overfullrule 0pt
\noindent
$$
\eqalign{
v(n) &= x(n) - a_1 v(n - 1) - a_2 v(n - 2) \cr
y(n) &= b_0 v(n) + b_1 v(n - 1) + b_2 v(n - 2)
}
$$
\bye