Solve the system using substitution and describe your steps:
x = y -3
2x + y = 12
+486 Taking $x=y-3$ and plugging it into $2x+y=12$ gives $2(y-3)+y=12$, so $2y-6+y=12$, $3y=18$, $\boxed{y=6}$.
Now, because $x=y-3$, $x=(6)-3$, $\boxed{x=3}$
+486 Taking $x=y-3$ and plugging it into $2x+y=12$ gives $2(y-3)+y=12$, so $2y-6+y=12$, $3y=18$, $\boxed{y=6}$.
Now, because $x=y-3$, $x=(6)-3$, $\boxed{x=3}$
