Question

Factor the polynomial completely

Answer 1

We have $2x^2-8$.

First let us factor the 2 to obtain,

$2(x^2-4)$

We can now see clearly that the expression inside the parentheses is a difference of two squares.

We now write the 4 as 2². So that we obtain the expression,

$2(x^2-2^2)$

Recall that

$a^2-b^2=(a+b)(a-b)$

Hence our expression becomes,

$2(x+2)(x-2)$

Therefore, when factored completely,

$2x^2-8=2(x+2)(x-2)$