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How to factor $2x^2 - 8y^2$ ?

So far I got it down to $$2(x^2 - 4y^2),$$ but it's not the answer; I don't think it's factored enough.

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    It can also be written as $2(x + 2y)(x - 2y)$, man.2011-11-15
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    The fact that $a^2-b^2=(a-b)(a+b)$ is the most important of the factoring ideas.2011-11-15

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