Объяснение:
12-y/6y-36 - 6/y²-6y= (12-y)/6(y-6) - 6/y(y-6)=
=(12y-y²-36) / 6y(y-6)= -(y²-12y+36)/6y(y-6) =
=-(y-6)² / 6y(y-6) = (6-y) /6y
