Respuesta :

geoplosion
assuming in the second bracket, 3y is to the power of 4:
you put each power seperatly:
5y^4+(-3y^4)
-3y^3+6y^3
2y^2+(-4y^2)
-6y+-4y
5+(-8)

you get:
2y^4
3y^3
-2y^2
-10y
-2

so the answer is 2y^4+3y^3-2y^2-10y-2