Answer:
(x - 3)(x - 12)
Step-by-step explanation:
Assuming you require to factor the expression
x² - 15x + 36
Consider the factors of the constant term (+ 36) which sum to give the coefficient of the x- term (- 15)
The factors are - 3 and - 12, since
- 3 × - 12 = + 36 and - 3 - 12 = - 15 , then
x² - 15x + 36 = (x - 3)(x - 12) ← in factored form
