Answer:
x² - 10x + 25
Explanation:
Given
(x - 5)² = (x - 5)(x - 5)
Each term in the second factor is multiplied by each term in the first factor, that is
x(x - 5) - 5(x - 5) ← distribute both parenthesis
= x² - 5x - 5x + 25 ← collect like terms
= x² - 10x + 25