Question

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

Answer 1

`(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 .

Answer 2

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)`