(3y - 8) y
---------- = ----------
12 5
cross multiply
5(3y - 8) = 12y.....distribute thru the parenthesis
15y - 40 = 12y ....subtract 15y from both sides
-40 = 12y - 15y....simplify
-40 = -3y ....divide both sides by -3
-40/-3 = y
13 1/3 (or 13.333) = y
