Answer:
w² - 13w + 36
Step-by-step explanation:
Given
(w - 9)(w - 4)
Each term in the second factor is multiplied by each term in the first factor, that is
w(w - 4) - 9(w - 4) ← distribute both parenthesis
= w² - 4w - 9w + 36 ← collect like terms
= w² - 13w + 36