25. (x + 1) (x + 2) (x + 3)

Решение: (x + 1)(x + 2)(x + 3) = (x + 1)[x(x + 3) + 2(x + 3)] = (x + 1)[x^2 + 3x + 2x + 6] = (x + 1)(x^2 + 5x + 6) = x(x^2 + 5x + 6) + 1(x^2 + 5x + 6) = x^3 + 5x^2 + 6x + x^2 + 5x + 6 = x^3 + 6x^2 + 11x + 6 Ответ: x^3 + 6x^2 + 11x + 6