Answer:
h² + 9h + 23
Step-by-step explanation:
Given
f(x) = x² + 3x + 5
To evaluate f(3 + h) substitute x = 3 + h into f(x), that is
f(3 + h) = (3 + h)² + 3(3 + h) + 5 ← expand (3 + h)² using FOIL
= 9 + 6h + h² + 9 + 3h + 5 ← collect like terms
= h² + 9h + 23
