Let:
[tex]\begin{gathered} P=(-2,-9) \\ Q=(-7,-4) \\ P^{\prime}=(9,2) \\ Q^{\prime}=(4,7) \end{gathered}[/tex]so:
[tex]\begin{gathered} P\to(x,y)\to P^{\prime} \\ -2+x=9 \\ so\colon \\ x=11 \\ ----- \\ -9+y=2 \\ y=11 \end{gathered}[/tex]Therefore:
[tex](x,y)\to(11,11)[/tex]