plz help срочно нужно

(y²-10y+25)/(y²-25)÷(7y-35)/(y²+5y)=(y-5)²/(y-5)·(y+5)÷(7·(y-5))/(y·(y+5))=
=[(y-5)²·y·(y+5)]÷[(y+5)·(y-5)·7·(y-5))]=сокращаем=y÷7
при y=3,5  3,5·÷7=3,5÷7=0.5