How do you factor the trinomial x^2 - 16 ?

2 Answers
Dec 3, 2015

(x+4)(x-4).

Explanation:

We use (a+b)(a-b) for this type of operation. To do this, we have to find the way to put numbers squared. x is already squared, but 16 has to be put as 4^2. Now, a = x and b = 4. So, we substitute:
(x+4)(x-4).

Hope it Helps! :D .

Dec 3, 2015

Apply the difference of squares formula to find that
x^2 - 16= (x+4)(x-4)

Explanation:

The difference of squares formula states that
a^2 - b^2 = (a+b)(a-b)
(try multiplying the right side out to verify this)

As 16 = 4^2 we have

x^2 - 16 = x^2 - 4^2 = (x+4)(x-4)