Answer :
Y=-5 because you add 7 to both sides to get -3y=15 and if you divide that you get y=-5
So you are first going to move the 7 to the other by adding it to 8. and 7 plus 8 equals 15. and then you are going to get Y by itself. and then you are going to divide 15 by 3 which equals 5. and thats your answer!!