3 3 x - 27*y
x^3 - 27*y^3 при y = 1/3
x^3 - 27*y^3
x^3 - 27*(1/3)^3
-1 + x^3
x^3 - 27.0*y^3
/ 2 2 \ (x - 3*y)*\x + 9*y + 3*x*y/