To solve for y, we have to move all of the terms that do not equal to y on one side, and let y be on the other side alone. Do this by subtracting 3x on both sides to cancel it out from the left side and bring it to the right.
To solve for x, we will do the same thing we did to solve for y: move all the terms that do not equal to x to one side, and leave x on another side of the equation. We can do this by first subtracting y from both sides.
Then, we divide all terms by 3 to isolate the x.