Respuesta :

( 4 x² + 12 x - 9 ) + ( 7 x² - x + 3 ) =
= 4 x² + 12 x - 9 + 7 x² - x + 3 =
= 11 x² + 11 x - 6
Answer:
D ) 11 x² + 11 x - 6

the answer is 11x^2+11x-6