Calculate heat of formation of \(\text{SO}_2\) from following equations.
\( \text{S} + \frac{3}{2}\text{O}_2 \longrightarrow \text{SO}_3, \Delta \text{H} = -2\text{x kJ} \)
\( \text{SO}_2 + \frac{1}{2}\text{O}_2 \longrightarrow \text{SO}_3, \Delta \text{H} = -\text{y kJ} \)