Answer :

Alright, let's simplify the given expression step by step.

The original expression is:

[tex]\[ \frac{a^2 \left(3^{a-8} \cdot 3^{a+9}\right)}{3^{2a} \cdot a} \][/tex]

### Step 1: Simplify the Expression inside the Parentheses

First, we need to simplify the term inside the parentheses, [tex]\(3^{a-8} \cdot 3^{a+9}\)[/tex].

Recall the property of exponents: [tex]\(b^m \cdot b^n = b^{m+n}\)[/tex]. So,

[tex]\[ 3^{a-8} \cdot 3^{a+9} = 3^{(a-8) + (a+9)} \][/tex]

Now, combine the exponents:

[tex]\[ (a-8) + (a+9) = a + a - 8 + 9 = 2a + 1 \][/tex]

Thus,

[tex]\[ 3^{a-8} \cdot 3^{a+9} = 3^{2a+1} \][/tex]

### Step 2: Substitute the Simplified Expression back

Now we substitute [tex]\( 3^{2a+1} \)[/tex] back into the original fraction:

[tex]\[ \frac{a^2 \cdot 3^{2a+1}}{3^{2a} \cdot a} \][/tex]

### Step 3: Simplify the Overall Fraction

Next, we simplify the overall fraction [tex]\(\frac{a^2 \cdot 3^{2a+1}}{3^{2a} \cdot a}\)[/tex].

We can split the fraction into two parts for easier simplification:

[tex]\[ \frac{a^2}{a} \cdot \frac{3^{2a+1}}{3^{2a}} \][/tex]

#### Simplify [tex]\(\frac{a^2}{a}\)[/tex]

The term [tex]\(\frac{a^2}{a}\)[/tex] simplifies to:

[tex]\[ \frac{a^2}{a} = a \][/tex]

#### Simplify [tex]\(\frac{3^{2a+1}}{3^{2a}}\)[/tex]

Using the properties of exponents again, [tex]\( \frac{b^m}{b^n} = b^{m-n} \)[/tex]:

[tex]\[ \frac{3^{2a+1}}{3^{2a}} = 3^{(2a+1) - 2a} = 3^1 = 3 \][/tex]

### Step 4: Combine the Results

Now we combine the simplified terms:

[tex]\[ a \cdot 3 = 3a \][/tex]

### Final Answer

Therefore, the simplified form of the original expression is:

[tex]\[ \boxed{3a} \][/tex]