2(5-y²) (у²+5) + (y² - 3)² - (y² + y - 1) (4- y²) =
= (10 - 2y²)(y² + 5) + y⁴ - 6y² + 9 - 4y² - 4y + 4 + y⁴ + y³ - y² =
= 10y² + 50 - 2y⁴ - 10y² + y⁴ - 6y² + 9 - 4y² - 4y + 4 + y⁴ + y³ - y² =
= 50 - 6y² + 9 - 4y² - 4y + 4 + y³ - y² =
= y³ - 11y² - 4y + 63