Выражение: 1) (a+1)(a²-a+1)-a³ 2) (x+y)(x²-xy+y²)-x(x²+y²) 3) (m-2)(m²+2m+4)+8 4) (c+3)(c²-3c+9)-27

(a+1)(a²-a+1)-a³=a^3+1^3-a^3=1

(x+y)(x²-xy+y²)-x(x²+y²)=x^3+y^3-x^3-xy^2=y^2(y-x)

(m-2)(m²+2m+4)+8=m^3-2^3+8=m^3-8+8=m^3

(c+3)(c²-3c+9)-27=c^3+3^3-27=c^3+27-27=c^3