Упростите выражение:
а) (a-2)(a^2+a-1)-a^2(a-1)

б) (3-p)(9+3p+p^2)-(1-p^3)

a) a^3-2^3-a^3+a²=a²-8b) 3^3-p^3-1+p^3=27-1=26

a)(a-2)(a²+a-1)-a²(a-1)=a³+a²-a-2a²-2a+2-a³-a²=-3a+2б)(3-p)(9+3p+p²)-(1-p³)=27+9p+3p²-9p-3p²-p³-1+p³=27-1=26