3.

(6/у*2-9 - 1/3-y) * (y*2+6y+9)/5

(6/(y+3)*(y-3) - 1/(y-3)) * (y+3)*2/5

(6-1(y+3)) / (y+3)(y-3) * (y+3)*2/5

(6-1(y+3)) / (y-3) * (y+3)/5

6(y+3) - 1(y+3)*2/ 5(y-3)

6y +18 - (y*2 +6y +9) /5(y-3)

6y + 18 -y*2 -6y -9 / 5(y-3)

9-y*2 / 5(y-3)

-(y-3)(y+3)/5(y-3)

Ответ: - (y+3)/5

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