Respuesta :

[tex](3a^2-ab-2b^2) + (2a^2+5ab-3b^2) - (a^2-3ab-4b^2)[/tex]

First we distribute the negative throughout the last polynomial:

[tex](3a^2-ab-2b^2) + (2a^2+5ab-3b^2) + (-a^2+3ab+4b^2)[/tex]

Combine like terms:

[tex]4a^2 + 7ab - b^2[/tex]