How do you factor the trinomial x^2 - 16 x2−16?

2 Answers
Hugo C.
Dec 3, 2015

(x+4)(x-4)(x+4)(x−4).

Explanation:

We use (a+b)(a-b)(a+b)(a−b) for this type of operation. To do this, we have to find the way to put numbers squared. xx is already squared, but 1616 has to be put as 4^242. Now, a = xa=x and b = 4b=4. So, we substitute:
(x+4)(x-4)(x+4)(x−4).

Hope it Helps! :D .

sente
Dec 3, 2015

Apply the difference of squares formula to find that
x^2 - 16= (x+4)(x-4)x2−16=(x+4)(x−4)

Explanation:

The difference of squares formula states that
a^2 - b^2 = (a+b)(a-b)a2−b2=(a+b)(a−b)
(try multiplying the right side out to verify this)

As 16 = 4^216=42 we have

x^2 - 16 = x^2 - 4^2 = (x+4)(x-4)x2−16=x2−42=(x+4)(x−4)

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