what is the correct answer for shifting and scaling this signal?
The sequence $x[n]$ is only non-zero in the range $-3\le n\le 3$. So if you change the index to $3n-1$, in order to remain inside that region, $n$ can only take the values $n=0$ (giving $3n-1=-1$), and $n=1$ (giving $3n-1=2$). This gives

$$x[3n-1]=\begin{cases}x[-1]=1,&amp;n=0\\x[2]=2,&amp;n=1\\
0,&amp;\text{otherwise}\end{cases}$$

So if the exercise is as you stated it, then your solution is correct, apart from the fact that it is not $3n-1$ but $n$ that takes the values $0$ and $1$.