6a²+3ab²-4ab-2b³ если а= -1 1/8 b= -1 1/2

6a^2+3ab^2-4ab-2b^3=3a(2a+b^2)-2b(2a+b^2)=(2a+b^2)(3a-2b)=(-2*11/8+121/4)(-3*11/8+22/2)=189.0625