There are an infinite number of solutions. The second equation is just -2 times the first equation. Choose a value for $x$, and then $y = 3+\dfrac{2}{3}x$.

The answer given doesn't even satisfy the given equations. Plugging into the first equation:

$-2\left(\dfrac{13}{2}\right) + 3\left(\dfrac{3}{2}\right) = -\dfrac{17}{2} \neq 9$.