Question

Factor completely x2 + 16. (x + 4)(x + 4) (x + 4)(x − 4) Prime (x − 4)(x − 4)

Answer 1

It's prime because the constant term is positive and there is no middle term. If it were x^2 - 16, we could use (x+4)(x-4), but because 16 is positive, it cannot be factored