Помогитеее (x-1)(x^2 +x+1) a(b-c)+3(c-b)
1. (x-1)(x^2 + x +1) = x^3 - 1
2. a(b-c) + 3(c-b) = a(b-c) - 3(b-c) = (b-c)(a-3)