Factor.
64x12 + 27y3 = ( 4x4 )3 + ( 3y )3
This is a sum of cubes. a3 + b3 = (a + b)(a2 - ab + b2)
( 4x4 )3 + ( 3y )3
= ( 4x4 + 3y )( (4x4)2 - (4x4)(3y) + (3y)2 )
= ( 4x4 + 3y )( 16x8 - 12x4y + 9y2 )
