OpenSAT

To solve for $x + y$, we can use elimination. Multiplying the second equation by 3 gives us $3x - 3y = 3$. Adding this equation to the first equation, we get $5x = 15$. Dividing both sides by 5, we find $x = 3$. Substituting 3 for $x$ in the equation $x - y = 1$, we get $3 - y = 1$. Subtracting 3 from both sides and multiplying by -1 gives us $y = 2$. Therefore, $x + y = 3 + 2 = 5$.