How do you factor $2x^2-98$ ?

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Answer 1 · 2018-03-20T22:03:55

$2(x-7)(x+7)$

There's a common factor of 2 for both terms, so let's pull that out:
$2(x^2 - 49)$

Now, we know that $49 = 7^2$ , which means that we can use difference of squares! The difference of squares formula is
$a^2 - b^2 = (a-b)(a+b)$

With $a = x$ and $b = 7$ , this tells us that
$x^2 - 49 = x^2 - 7^2 = (x-7)(x+7)$

so our final factorization is
$2x^2 - 98 = 2(x-7)(x+7)$

How do you factor 2x^2-982x^2-98?