Equations of fraction

Algebra Level 2

$\large \begin{cases} \dfrac{x}{a} + \dfrac{y}{b} = \dfrac{2}{a} + \dfrac{1}{b} \\ \dfrac{x}{b} - \dfrac{y}{a} = \dfrac{2}{b} - \dfrac{1}{a} \end{cases}$

Solve the system of equations above for positive $x$ and $y$ .

Enter your answer as $x + y$