Answer:
[tex]f(3+h)= 14+18h+ h^{2} \\\\[/tex]
Step-by-step explanation:[tex]f(3+h)= (3+h)^{2} + 3(3h+h) +5\\= 9+6h+h^{2} +9h +3h +5= 14+18h+ h^{2} \\\\[/tex]