Respuesta :

To simplify the expression, we distribute terms accordingly. It is done as follows:

(3a – 4b)(a + b)
3a
² + 3ab -4ab -4b²
3a² - ab -4b²

Therefore, the correct answer is option A, 3a^2– ab – 4b^2. 

Hope this answers the question. Have a nice day. Please feel free to ask more questions.