Respuesta :

Answer:

-8y^7 - 5y^6 + 9y^5 + 3y^4 - 4y^3

Step-by-step explanation:

Please be sure to use " ^ " to indicate exponentiation.  Then,

your 9y5−4y3−8y7−5y6+3y4 becomes 9y^5 - 4y^3 - 8y^7 - 5y^6 + 3y^4.

We must now write that in descending order by powers of y:

-8y^7 - 5y^6 + 9y^5 + 3y^4 - 4y^3