a (a-2)(a+2)-(a-1)(a^2+a+1)
Ответ
0
(a-2)(a+2)=a²-4
(a-1)(a²+a+1)=a^3-1
a(a²-4)-(a^3-1)=
=a^3-4a-a^3+1=1-4a
(a-1)(a²+a+1)=a^3-1
a(a²-4)-(a^3-1)=
=a^3-4a-a^3+1=1-4a