Answer:
H^2+9H+23
Step-by-step explanation:
f(3+h)=(3+H)^2+3*(3+H)+5
=9+6H+H^2+9+3H+5
=H^2+9H+23
f(3+h)=(3+h)²+3(3+h)+5=9+6h+h²+9+3h+5=h²+9h+23
