x² - 20x + 100
Find two numbers, such that its sum gives -20 and its product gives 100
If such numbers exist, this implies that the polynomial is NOT prime
The two numbers are: -10 and -10
Replace the coefficient of x with the two numbers
x² - 10x -10x + 100
x(x-10) - 10(x - 10)
(x-10)(x-10)
(x-10)²
Therefore, the correct option is A.
x² - 20x + 100 = (x-10)²
