Standard slip for is y=Mx+b. For this what you would do is :
1. Subtract the 2y from the right side, now what you do to one side you do to the other, so you would end up with:
-2y+6x=24
(Because you subtracted 2y from both sides)
2. Now you subtract 6x from the left side, again what you do to the left you do to the right so now you end up with:
-2y = -6x + 24.
Let me know if this helped you! :D