Add: (3x2 - 5x + 6) + (9 - 8x - 4x2) A) 12x2 - 13x + 2 B) 7x2 + 3x - 3 C) 7x2 - 13x + 15 D) -x2 - 3x + 15 E) -x2 - 13x + 15

Add: (3x2 - 5x + 6) + (9 - 8x - 4x2)
The givens should be arranged first before we can start answering.
    3x2 - 5x + 6 plus
   -4x2 - 8x + 9
= -x2  - 13x +15
Therefore, the answer to the question is E) -x2  - 13x +15