Respuesta :

7y2+2y2+3-6y2-3y2-4
7y2+6y2+2y-3y+3-4
y2-y-1
7y^2 + 2y + 3 - 6y^2 - 3y - 4
(7-6)y^2 + (2-3)y + (3-4)
y^2 - y -1
C.