x2 - 4
x2 - 2 + 4 = x2 + 2This term can not be factored any further
X2 - 16(X - 4)(X + 4)============X2 + 16===========not factorable in real numbers
x3 + x2 + 4x + 4 = (x2 + 4)(x + 1)
(x + 4)(x - 4)
-3
x(x - 4)
That cannot be factored
x2-5x+4 = (x-1)(x-4) when factored
(x + 4)(x + 1)
It is: (x-4)(x+4)
x2 - 4x - 32 = (x - 8)(x + 4)