# How do you factor x^4-y^4?

Jul 28, 2016

=(x^2+y^2)(x+y)((x-y)
Since formula ${a}^{2} - {b}^{2} = \left(a + b\right) \left(a - b\right)$ can be applied here.
${x}^{4} - {y}^{4}$
$= {\left({x}^{2}\right)}^{2} - {\left({y}^{2}\right)}^{2}$
$= \left({x}^{2} + {y}^{2}\right) \left({x}^{2} - {y}^{2}\right)$
=(x^2+y^2)(x+y)((x-y)