Respuesta :

irspow
You only need to combine like terms, ie add terms that have the same bases and exponents...the terms in order of their magnitude:

-3x^4+9x^3+5x^2+7x-4x-4-6

-3x^4+9x^3+5x^2+(7x-4x)+(-4-6)  see how the groupings are at the end...

-3x^4+9x^3+5x^2+3x-10