How do you factor $9 x^{2} - 49$ $9x^2 - 49$ ?

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Answer 1 · 2015-05-02T04:43:46

$9 x^{2} - 49 = {(3 x)}^{2} - 7^{2}$ $9x^2 - 49 = (3x)^2 - 7^2$

We know the identity $a^{2} - b^{2} = (a + b) (a - b)$ $color(blue)(a^2 - b^2 = (a+b)(a-b)$

${(3 x)}^{2} - 7^{2} = (3 x + 7) (3 x - 7)$ $(3x)^2 - 7^2 = color(green)((3x +7)(3x - 7)$

How do you factor 9x^2 - 49 9x2−499x^2 - 49 ?