Question

Factor completely x2 - 36. I think this is Prime is that correct

Answer 1

$x^2 - 36=(x-6)(x+6)\\\\\\a^2-b^2 = (a-b)(a+b)$

Answer 2

No.  It's the difference of two squares, and so can be easily factored:

x² - 36 = (x + 6) (x - 6)

Multiply those out and you'll see.