Answer:
-10y^2-y-10
Step-by-step explanation:
Subtract the 1st equation from the 2nd:
D-C = (-7y^2+3y-6)-(3y^2+4y+4)
= -7y^2+3y-6-3y^2-4y-4
= (-7-3)y^2 + (3-4)y + (-6-4)
