Matrices and Determinants: JEE Main 2021 Mathematics question

If the system of linear equations 2x + y $-$ z = 3 x $-$ y $-$ z = $\alpha$ 3x + 3y + $\beta$z = 3 has infinitely many solution, then $\alpha$ + $\beta$ $-$ $\alpha$$\beta$ is equal to _____________.