Factor $64x^9 - 125y^6$ I'm trying to help my daughter with Algebra 2.  This is a homework assignment.  I've done a fair amount of searching but I just can't figure this out.  Mathway, an online tool gave the answer:
$(4x^3 - 5y^2) (16x^6 + 20x^3y^2 + 25y^4)$
I can pattern match a bit but can't figure out what's going on.  Would someone be willing to provide a link or explain what sort of procedure to follow to factor this expression?

Way to do this:
$a^3-b^3=(a-b)(a^2+ab+b^2)$
$64x^9 - 125y^6 = (4x^3)^3 - (5y^2)^3$
$= (4x^3 - 5y^2) [(4x^3)^2 + 4x^3 * 5y^2 + (5y^2)^2]$
$= (4x^3 - 5y^2) (16x^6 + 20x^3y^2 + 25y^4)$
