To solve the limit problem, we need to simplify the expression inside the limit. First, expand the numerator and then simplify the fraction. Finally, take the limit as \( h \) approaches 0.
Step 1: Expand the Numerator
First, we expand the expression \((9 + h)^2\):
\[
(9 + h)^2 = 81 + 18h + h^2
\]
Step 2: Simplify the Expression
Next, we substitute the expanded form back into the original limit expression:
\[
\frac{(9 + h)^2 - 81}{h} = \frac{81 + 18h + h^2 - 81}{h} = \frac{18h + h^2}{h}
\]
Step 3: Factor and Cancel \( h \)
We can factor \( h \) out of the numerator:
\[
\frac{18h + h^2}{h} = \frac{h(18 + h)}{h} = 18 + h
\]
Step 4: Take the Limit as \( h \) Approaches 0
Finally, we take the limit of the simplified expression as \( h \) approaches 0:
\[
\lim_{h \to 0} (18 + h) = 18
\]