3 8*m 3 ---- + n 27
(8*m^3)/27 + n^3 при m = -1/3
(8*m^3)/27 + n^3
(8*(-1/3)^3)/27 + n^3
-8/729 + n^3
n^3 + 0.296296296296296*m^3
3 3 8*m + 27*n ------------ 27
/ 2 2 \ (2*m + 3*n)*\4*m + 9*n - 6*m*n/ --------------------------------- 27