How do you factor $125x^3 + 216$ ?

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Answer 1 · 2015-04-22T02:00:46

$125x^3=5x$ and $216=6^3$

We can use the sum of cubes to factor $(125x^3+216)$ .

$(a^3+b^3)=(a+b)(a^2-ab+b^2)$

$a=5x$
$b=6$

$(5x+6)((5x)^2-(5x)(6)+6^2)$ =

$(5x+6)(25x^2-30x+36)$

How do you factor 125x^3 + 216125x^3 + 216?