Answer:
8( 3x+2y) ( 9x^2 -6xy +4y^2)
Explanation:
216x^3 + 64y^3
Factor out the greatest common factor of 8
8( 27x^3 +8y^3)
Rewriting
8 ( (3x)^3 + (2y)^2))
Recognizing this as the difference of cubes)
a^3 + b^3 = (a+b) (a^2-ab+b^2)
8 ( (3x)^3 + (2y)^2)) = 8( 3x+2y) ( 9x^2 -(3x)(2y) +4y^2)
=8( 3x+2y) ( 9x^2 -6xy +4y^2)