Given:
(y- 2) ( y² - 4y - 9)
Open the parenthesis
y(y² - 4y - 9) - 2(y² - 4y - 9)
y³ - 4y² - 9y - 2y² + 8y + 18
Re-arrange and simplify
y³ - 4y² - 2y² - 9y + 8y + 18
y³ - 6y² - y + 18
Hence, the simplified polynomial in descending order is:
y^3 - 6y^2 - y + 18
The degree is the highest exponent.
Thererfore, the degree of this simplified answer is 3