Given a system of equations:

We have to solve the system of equations.
We can solve this system of equations using the substitution method.
From the second equation, we have x - y = -3, which implies that x = y - 3. Substitute x = y - 3 in the first equation:

Now, we have y = 3, put in x = y - 3 to get,

Thus, the solution of the system of equations is (0, 3).