Respuesta :

darkdragonex
In order to combine like terms you need to organize them so that it is easier to solve.

2x + 3x^2 + 5x^2 - x + 7
5x^2 + 3x^2 + 2x - x +7
8x^2 + x + 7

Your answer should be 8x^2 + x + 7