How do you factor $49 - 4x^2$ ?

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Answer 1 · 2015-05-12T04:41:51

This expression can be written as $7^2 - (2x)^2$

We know the difference of squares identity:

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

Hence $7^2 - (2x)^2 = color(green)((7+2x)(7-2x)$

How do you factor 49 - 4x^249 - 4x^2?