Respuesta :

Answer:

The answer is C.

Step-By-Step Explanation:

Once you combine the like terms of 5x^2-8x-7 and 2x^2-3x-7 you get 7^2-11x-5. Then you need to subtract x^2-9x-4 from 7^2-11-5x. Then you will get the answer which is C.

Answer:

  C.  6x² -2x -1

Step-by-step explanation:

You want the sum of ...

  (5x² -8x +2) + (2x² -3x -7) - (x² -9x -4)

Eliminating parentheses gives ...

  5x² -8x +2 +2x² -3x -7 -x² +9x +4

Grouping like terms, we have ...

  (5x² +2x² -x²) + (-8x -3x +9x) + (2 -7 +4)

Then combining like terms gives ...

  6x² -2x -1 . . . . matches choice C