Respuesta :

Answer:

6. 4x^2 + x - 1
7. 3x^2 + 4x + 4

Explanation:

(3x^2 + x + 8) + (x^2 - 9)
4x^2 + x - 1

(5x^2 + 8x - 2) - (2x^2 - 4x + 6)
3x^2 + 4x + 4