Solve this:

Dear student,
Here is the solution of your asked query:
$$\begin{gathered} {\mathrm{p}}^2+{\mathrm{q}}^2-{\mathrm{r}}^2 \\ ={\left(-2\right)}^2+{\left(-1\right)}^2-3^2 \\ =4+1-9 \\ =-4 \end{gathered}$$
Regards