Answer:
x² - 9x + 20
Step-by-step explanation:
Given
(x - 5)(x - 4)
Each term in the second factor is multiplied by each factor in the first factor, that is
x(x - 4) - 5(x - 4 ) ← distribute both parenthesis
= x² - 4x - 5x + 20 ← collect like terms
= x² - 9x + 20