Выражения: (2x+1)(x-1) (3-y^2)(y-4) a^2+(2-a)(a+5) (n-1)(n^2+n-2)

1)(2x^2-x-1)(3y-12-y^3-4y^2)

1) (2х+1)(х-1)=2х^2-2х+х-1=2х^2-х-1 2)=3у-12-у^3+4у^2=у^3-4у^2-3у+12 3) а^2+2а+10-а^2-5а=-3а+10 4)n^3+n^2-2n-n^2+n+2= n^3-2n+n+2