22 Find the value of the integer $n$ for the following pair of simultaneous equations to have no solution.
$$
\begin{array}{l}
2 x=1+n y, \\
n x=1+2 y .
\end{array}
$$
22. Answer: -2
Adding the 2 equations and simplifying gives $(n+2)(x-y)=2$. Hence if $n=-2$, we get $0=2$ which is impossible.