(7w3-4w+3)+(5w3-3w-3)
that is a simple polynomial addition:(7w3-4w+3)+(5w3-3w-3)= (7w^3 - 4w + 3) + (5w^3 - 3w - 3)= 7w^3 - 4w + 3 + 5w^3 - 3w - 3= 12w^3 - 7w= w(12w^2 - 7)