4y/(y-6) + 1 = 7y/(y-6)
multiply both sides by y-6, you get
4y + y - 6 = 7y
collecting like terms gives
5y - 6 = 7y
subtract both sides by 7y gives
5y - 7y - 6 = 0
collect like terms and add 6 to both sides gives
-2y = 6
divide both sides by -2 gives
y = -3