**Решение:**
**a) (y² + y + 2)(y+3)**
$$(y^2 + y + 2)(y+3) = y^2(y+3) + y(y+3) + 2(y+3) = y^3 + 3y^2 + y^2 + 3y + 2y + 6 = y^3 + 4y^2 + 5y + 6$$
**Ответ: y³ + 4y² + 5y + 6**
**б) (x+1)(x²-x+1)**
$$(x+1)(x^2-x+1) = x(x^2-x+1) + 1(x^2-x+1) = x^3 - x^2 + x + x^2 - x + 1 = x^3 + 1$$
**Ответ: x³ + 1**