Объяснение:
(2y+3y)/(7y²+ay)=(5y)/(y(7y+a))=5/(a+7y)
(3a-2)/(18-27a)=(3a-2)/(-9(3a-2))=-1/9
(y²-25)/(2y-10)=((y-5)(y+5))/(2(y-5))=(y+5)/2
