With the information given, we know that
[tex]\begin{gathered} x+y=45 \\ \text{and} \\ x-y=13 \end{gathered}[/tex]This way, we'll have the following system of equations:
[tex]\begin{cases}x+y=45 \\ x-y=13\end{cases}[/tex]Adding up both equations ansd sol, we get: