(1) 64x^6-y^6=8^2(x^3)^2-(y^3)^2=(8x^3-y^3)(8x^3+y^3)
(2) p^6+1\64k^6= (p^2)^3+ 1/4^3(k^2)^3=(p^2+1/4k^2)(p^4-1/4p^2k^2+1/16k^4)
