3 + 12 (y-4) = 40
*Use distribution*
3 + 12y - 48 = 40
*combine like terms*
-45 + 12y = 40
* what you do to one side of the equation you have to do to the other side
-45 +12y = 40
+45 +45
-----------------------
12y = 85
*now you divide to isolate variable*
85
------- = 7
12
Y =7
