Question

(у^2-2у)^2-у^2(у+3)(у-3)+2у(2у+5)

Answer 1

$(y^2-2y)^2-y^2(y+3)(y-3)+2y(2y+5)$ = $y^4-4y^3+4y^2-y^2(y+3)(y-3)+2y(2y+5)$ = $y^4-4y^3+4y^2-y^2(y^2-9)+4y^2+10y$ = $y^4-4y^3+4y^2-y^4+9y^2+4y^2+10y$ = $-4y^3+8y^2+9y^2+10y$ = $-4y^3+17y^2+10y$