Well you are solving for Y so you have to get y by itself. So in order to do that you must multiply both sides by 3/2. You do this because you need to get 2/3 on the other side. So just multiply -12 and 2/3 and you'll get y=-18. You can check this by plugging -18 into your original equation. So 2/3y=-12 will become 2/3(-18)=-12. If the you got the correct answer then you should get -12=-12.
