Respuesta :

Answer:

-x^2+5x

Step-by-step explanation:

Okay. Let us start by underlining those like terms:

7x^2 - 5x +10x  -8x^2

7x^2-8x^2     -5x+10x (I basically grouped the like terms together)

-x^2    +5x (I solved it in those groups)

-x^2+5x   (answer)