(x+y)=(x^(1/3)+y^(1/3))(x^2/3+y^2/3-(xy)^1/3)=((x^1/3+y^1/3)^2-3(xy)^1/3)(x^1/3+y^1/3)=(16-3(xy)^1/3)*4=28
16-3(xy)^1/3)=7
3(xy)^1/3=9
(xy)^1/3=3
xy=3^3=27
(x+y)=(x^(1/3)+y^(1/3))(x^2/3+y^2/3-(xy)^1/3)=((x^1/3+y^1/3)^2-3(xy)^1/3)(x^1/3+y^1/3)=(16-3(xy)^1/3)*4=28
16-3(xy)^1/3)=7
3(xy)^1/3=9
(xy)^1/3=3
xy=3^3=27