How do you factor $x^2 +8x -24$ ?

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Answer 1 · 2016-08-28T20:13:32

$x^2+8x-24=(x+4-2sqrt(10))(x+4+2sqrt(10))$

The difference of squares identity can be written:

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

Use this with $a=(x+4)$ and $b=2sqrt(10)$ as follows:

$x^2+8x-24$

$=x^2+8x+16-40$

$=(x+4)^2-(2sqrt(10))^2$

$=((x+4)-2sqrt(10))((x+4)+2sqrt(10))$

$=(x+4-2sqrt(10))(x+4+2sqrt(10))$

How do you factor x^2 +8x -24x^2 +8x -24?