Respuesta :

Answer:

[tex] - 2 {b}^{3} [/tex]

Step-by-step explanation:

[tex]a^3−b^3−3ab−(a^3+b^3−3ab)[/tex]

[tex]=(a^3)+(−a^3)+(−b^3)+(−b^3)+(−3ab)+(3ab)[/tex]

[tex]= - 2 {b}^{3} [/tex]

Hope it is helpful....