(−8* y^2−9*y)+(8*y^3+9*y^2−2*y) first, remove extraneous parentheses (or distribute if negative) =−8* y^2−9*y+8*y^3+9*y^2−2*y then group terms in decreasing degree of y (variable) =+8*y^3 −8* y^2+9*y^2 −9*y−2*y simply expression by adding/subtracting similar terms =+8*y^3 +y^2 −11*y to give the final answer.
