Answer:
A
Explanation:
x² - 12x + 36
consider the factors of the constant term (+ 36) which sum to give the coefficient of the x- term (- 12)
the factors are - 6 and - 6 , since
- 6 × - 6 = + 36 and - 6 - 6 = - 12 , then
x² - 12x + 36
= (x - 6)(x - 6)
= (x - 6)²