How do you factor: $y= x^2-4$ ?

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Answer 1 · 2018-03-22T18:32:00

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

Notice we can write:

$x^2-4\ \ \ \$ as $\ \ \ \ x^2-2^2$

This is the difference of two squares:

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

$:.$

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

How do you factor: y= x^2-4 y= x^2-4 ?