Упростите выражение (3-y)(y+3y+y^2)-(3-y)(3+y)+y^3
(3-y)(y+3y+y²)-(3-y)(3+y)+y³ 3y+9y+3y²-y²-3y²-y³-9-y²+y³ 12y-2y²-9 -2y²+12y-9