Respuesta :

Answer:

Dannielle's mistake was that she added the exponents,

x^3 + 5x^3, doesn't equal 6x^6

Step-by-step explanation:

the correct work is below:

x^3 + 5x^3 + 5x^2 - 3x^2 + 2x - 7 - 1

6x^3 + 2x^2 + 2x -8