# How do you factor 250x^4 +128x?

Nov 23, 2016

$250 {x}^{4} + 128 x$

$= 2 x \left(125 {x}^{3} + 64\right)$

Use the rule : a^3 + b^3 = (a + b)(a^2 – ab + b^2)
$= \left(2 x\right) \left[{\left(5 x\right)}^{3} + {\left(4\right)}^{3}\right]$

$= \left(2 x\right) \left(5 x + 4\right) \left({\left(5 x\right)}^{2} - \left(5 x\right) \left(4\right) + {4}^{2}\right)$

$= \left(2 x\right) \left(5 x + 4\right) \left(25 {x}^{2} - 20 x + 16\right)$