G4.2 If $9 x^{2}+n x+1$ and $4 y^{2}+12 y+m$ are squares with $n>0$, find the value of $\frac{n}{m}$.
$\begin{array}{l}9 x^{2}+n x+1=(3 x+1)^{2} \Rightarrow n=6 \\ 4 y^{2}+12 y+m=(2 y+3)^{2} \Rightarrow m=9 \\ \frac{n}{m}=\frac{2}{3}\end{array}$