Taking LCM of 4 and 1 on LHS = 4 and 1 and 2 on RHS = 2

By cross multiplication

⇒ 3y - 15 - 16y = 2(9 - y)

⇒ - 13y + 2y = 18 + 15

⇒ - 11y = 33

⇒ y = - 3